Songrium: Browsing and Listening Environmentfor Music Content Creation Community
Masahiro Hamasaki
Masataka Goto
Tomoyasu Nakano
National Institute of Advanced Industrial Science and Technology (AIST), Japan{masahiro.hamasaki, m.goto, t.nakano}[at]aist.go.jp

ABSTRACTThis paper describes a music browsing assistance service,
Songrium (http://songrium.jp), which enables visualization and exploration of large amounts of user-generated
music content with the aim of enhancing user experiences in enjoying music. Such a huge amount of usergenerated content has yielded “web-native music”, which
we define as musical pieces that are published, shared,
and remixed (have derivative works created) entirely on
the web. Songrium has two interfaces for browsing
and listening to web-native music from the viewpointsof scale and time: Songrium3D for gaining communityscale awareness and Interactive History Player for gaining community-history awareness. Both were developed
to stimulate community activities for web-native music byvisualizing large amounts of music content spatially or
chronologically and by providing interactive enriched experiences. Songrium has analyzed more than 680,000 music video clips on the most popular Japanese video-sharing
service, Niconico, which includes original songs of webnative music and their derivative works such as covers anddance arrangements. Analyses of more than 120,000 original songs reveal that over 560,000 derivative works havebeen generated, contributing to the enrichment of usergenerated music content.
1. INTRODUCTION
When many amateur musicians started releasing their new
original songs on video-sharing services, a new type ofmusic content that was born, listened to, and distributedon the web became popular. Many derivative works suchas cover versions and music video clips of those songs
have also been created and shared actively by other creators. Such music contents, called web-native music [1],have continued to increase. The contents differ from commercially distributed songs, which are released originallyon the market and are then copied to video-sharing services.
Creators and listeners of web-native music form an interesting community that grows and continues to update
its own history dynamically on the web. This dynamics
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Figure 1. Songrium3D and Interactive History Player. The
former is scale-aware visualization. The latter is timeaware visualization for music content creation community.

makes it difficult for people to grasp a comprehensive picture of the community. Although ranking and recommendation are powerful and typical ways to find popular andsimilar music contents, they are insufficient to elucidate
the entire community. The goal of this research is to enablepeople to browse and listen to web-native music efficiently
while grasping its nature and history.
This paper therefore presents a proposal to extend our
web service, Songrium (http://songrium.jp) [1, 2], byadding Songrium3D and Interactive History Player, twointerfaces that help people to be aware of the scale andhistory of the music content creation community throughvisualization of music content. Songrium3D presents visualization of the whole content in three-dimensional (3D)

space to facilitate community-scale awareness (Fig. 1-A).
Interactive History Player visualizes the content chronologically to gain community-history awareness (Fig. 1B). The current target content of Songrium is original
songs using VOCALOID [3] singing synthesis technology
and their derivative works on Niconico, the most popular
Japanese video-sharing service.
Songrium3D visualizes original songs as if they are stars
in a planetarium. Their positions are arranged automatically so that songs with similar moods can be closely
located. Additionally, it seamlessly visualizes overviewsof the whole content and details of each content. Furthermore, Songrium3D shows automatically synthesizedvisual effects for each user-generated music content during music playback. The effects comprise predefined elements. Their compositions are based on the analysis ofmusic structure, both contributing to high-quality visuals.
Interactive History Player shows growth in the popularity of songs, arranged by published date, in an animateddisplay. This feature enables users to experience a groupof songs in one continuous movie, providing a clear, intuitive picture of how trends related to video-sharing services
have changed.
We launched Songrium in August 2012. More than
147,000 users have used our service since. More than
120,000 original songs and 560,000 derivative works havealready been registered. New songs are also registered automatically every day. For those reasons, Songrium is the
only large-scale web service that can provide a comprehensive overview of the music content creation community for
VOCALOID.
This paper is organized as follows. Section 2 explains
music content creation community within the VOCALOID
community on Niconico. Section 3 introduces basic functions provided by Songrium. Section 4 presents a description of Songrium3D. Section 5 presents a description ofInteractive History Player. Section 6 presents our experiences with Songrium. Section 7 presents related work.
Section 8 presents a summary of this paper’s contributions.
2. WEB-NATIVE MUSIC ON NICONICO
Niconico is an extremely popular video communication
service in Japan today. As with similar services (YouTube
LLC, etc.), users can upload and view videos. Usergenerated music content is the subject of many videos.
Among them, music contents related to VOCALOID are
popular. They differ from the rest, as explained below.
VOCALOID is a singing synthesis technology [3] andit is used to synthesize the main vocal melody of songs.
Many examples have been published as original works
on the web. Despite the impressive technology used forthe songs, the vocals produced by VOCALOID are readily identifiable as not of human origin, meaning that bothcreators and listeners naturally accept that these songs are
first published on the web. Niconico therefore serves as
a common space for VOCALOID creators and listeners to
do meeting, communication and even collaboration as we
discuss later.

Figure 2. Two top graphs show that the total number ofpublished original songs and their derivative works in the
period September 2007 – December 2014. The two bottom graphs show the monthly number of published original
songs and their derivative works in 2014.

Many different singing synthesis products are based on
VOCALOID; each has a different vocal timbre. Most
products have an associated character image, with Hatsune
Miku1 being the most well-known. Soon after releasing
Hatsune Miku, Crypton Future Media (the developer of
Hatsune Miku) officially started allowing users to reuse its
character for derivative works with their original license:
Piapro Character License2 . Subsequently, users started tocreate music videos for Hatsune Miku, with such original
songs and drawings. Some users even went so far as to create 3D models of Hatsune Miku and to create 3D animation videos [4, 5]. Thereafter, many songwriters publishedkaraoke (full song without vocals) versions of their own
original songs, prompting some users to sing these songs
and to publish derivative works recorded in video clips.
We designated music having such characteristics as webnative music [1] and defined the conditions of web-native
music as shown below.
(1) It is generally assumed that new original songs are
first released on the web (without CD release or radio play, for example), with a unique URL identifying the source and release date.
(2) Creators do not hesitate to create and release derivative works of original songs on the web.
(3) After releasing original or derivative works, theircreators can publicly receive feedback on the web
and be encouraged to create more related materials.
Under the conditions described above, web-native music naturally encourages the creation of derivative works.
In fact, many derivative works are uploaded on Niconico. Figure 2 shows the number of total published original songs and their derivative works from September 2007
1 http://www.crypton.co.jp/mp/pages/prod/vocaloid/cv01 us.jsp
2 From December 2012, they use Creative Commons license for foreign users.

Table 1. Classification results of 564,623 derivative works.
Some derivative works have multiple categories. Therefore, the total number of classifications is greater than thenumber of derivative works.
category# of works(a) Singing
379,342(b) Dancing
30,15935,584(c) Arranging and Performing(d) Featuring 3D characters33,270(e) Creating Music video
9,062(f) Others
84,137

Figure 3. System overview of Songrium.

through December 2014 and the number of monthly published items in 2014. As described herein, we define theterm ‘derivative work’ as a video clip that reuses a partof or whole of video clip of VOCALOID original song.
According to this figure, the number of uploaded original
songs and derivative works has been increasing constantly.
In 2014, about 1,500 original songs and 7,000 derivative
works were published month by month. 80% of derivative
works are published after one month past the original publication date, whereas 40% are published after one year,
showing that derivative works help original works to keep
the attention of audiences for long periods. Furthermore,
14% of original songs have a derivative work with pageviews higher than the original work, indicating that derivative works are attractive contents.
3. SONGRIUM
3.1 Overview
Songrium, a music browsing assistance service, facilitates
understanding of the great amounts of user-generated music content within the VOCALOID community on the
Niconico service. Figure 3 portrays an overview ofSongrium. Songrium automatically gathers information
related to original songs and their derivative works, which
are expanding day-by-day. It then classifies these contents and estimates the relations between original songs
and derivative works. Songrium presents a visualization
using results obtained from music understanding.
By visualizing the web-native music, Songrium improvesa user’s understanding of various relations in the webnative music and enriches an interactive experience in themusic content creation community. It was difficult for people listening to original songs to notice that there exist various derivative works related to them, such as cover versions, singing or dancing video clips, and music video clips
with 3D animations. By providing people with easy, intuitive access to those derivative works, Songrium enables

them not only to find interesting music video clips but also
to know and respect the creators of music and video clips.
Songrium uses web mining and music understanding
technologies together with advanced data visualization
techniques to achieve unique function, such as a Music Star
Map, Songrium3D (in Section 4), and Interactive History
Player (in Section 5).
3.2 Web mining of Songrium
Every music video clip on Songrium is classified automatically as an original song or a derivative work. Social
tags of some kinds such as “Original Song” and “be enshrined in the Hall of Fame song” are usually put on original songs on Niconico. Therefore, these tags are reliable.
However, even if some original songs have no such tag,
Songrium automatically classifies them correctly by crawling a set of related web sites to generate the “white list”
of VOCALOID original songs. In the case of derivative
works, these can be readily identified when the description
text of the video clip includes a hyperlink to the originalvideo clip from which it was derived. These hyperlinks
almost always exist on Niconico because users prefer toacknowledge the original video clip.
When a derivative work is incorporated, its relation tothe original song is estimated automatically. The derivative works are classified into predefined categories. We
defined six categories of derivative works: (a) Singing asong, (b) Dancing to a song, (c) Performing a song on
musical instruments, (d) Featuring 3D characters in music video, (e) Creating a music video for a song, and (f)Others. The first three categories are derived from official
categories used by Niconico; the other two categories arederived from our previous work [4, 5]. “Others” includes,for example, videos which review or rank existing videos,or which is karaoke version, or which use VOCALOID
songs as the background music to other video contents. It
also includes videos that are not classifiable. With the exception of category Others all have their own unique social
tags on Niconico. Using these tags, Songrium can produce
a reliable classification of derivative works. Table 1 showsclassification results of derivative works.
Moreover, Songrium enables users to report an error in
any of the above classification of video clips, extraction oflinks, or estimation of relations easily to improve the user
experience further.

Figure 4. Screenshot of the (A) “Music Star Map” and (B) “Planet View” interface in Songrium: the former visualizes
original songs; the latter visualizes their derivative works. Both are connected seamlessly. (A) All original songs arearranged in a two-dimensional space with similar songs positioned in proximity. Any particular area can be expanded forviewing by double clicking. It can then be scrolled to by dragging. (B) After selecting an original song on Music Star Map,
users can view its derivative works rotating around the selected song in the center. (C) Embedded video player of Niconico
for video playback. (D) Playback interface for trial listening (SmartMusicKIOSK). (E) Social annotated relations called
Arrow tags [2] to and from this song instance.

3.3 Music Understanding and Visualization ofSongrium
Songrium has various functions of visualization for music
content [2] [1] using music audio analysis. Music Star Map
is a function that visualizes original songs. Original songs
are embedded in a two-dimensional space, mapped automatically based on audio feature similarity. The position ofeach original song is mapped to a two-dimensional spaceof the Music Star Map based on analysis of audio features.
Although any feature vector designed for computing music similarity could be used, in our current implementation,
we use a 200-dimensional audio feature vector obtainedusing learned latent representations [6]. To determine the(x–y) position of a song on the Music Star Map, its 200dimensional feature vector is projected onto two dimensions using principal component analysis (PCA), where
only the first two components are retained. Figure 4-(A)portrays a screenshot of this function.
When a user clicks an original song on Music Star Map,
its derivative works appear as colorful icons and orbit the
selected song. We designate this view as the “Planet View.”
Figure 4-(B) presents a Planet View screenshot. Each circle icon denotes a derivative work with attributes represented by the icon orbit, size, color, and velocity. Table 2
shows correspondence between visual features and metadata.
The official embedded video player of the Niconico service, shown at the upper-right corner, can play back a video
clip of the selected original song (Fig. 4-(C)). Our musiclistening interface has a chorus-search function for trial
listening, SmartMusicKIOSK [7], which is shown below
the embedded player (Fig. 4-(D)). Songrium has an original social tagging framework called the ‘Arrow Tag’ that

Table 2. Correspondence table with visual features of theicons and metadata of derivative works.
Visual feacture Metadata
Radius of orbit Publishing date
Size
Number of page views
Velocity
Number of favorite users
Derivative categories
Color
allows to annotate a relation between music content [2].
Figure 4-(E) shows a list of Arrow Tags.
4. SONGRIUM3D
Songrium3D is a novel visualization interface based on theMusic Star Map of Songrium . The Music Star Map visualizes original songs and their derivative works in twodimensional space, but Songrium3D visualizes them inthree-dimensional space. Using three-dimensional visualization, Songrium3D (1) visualizes many contents simultaneously, and (2) visualize songs, derivative works, andmusic structure seamlessly.
Figure 5 presents a screenshot of Songrium3D. The
spherical object represents an original song in the centerof the figure. When it plays a song, this object and peripheral objects move rhythmically, synchronized to the song.
The (x–y–z) position of a song is determined based on thefirst three principal components (see Section 3.3). Manycolorful circumjacent materials indicate derivative worksof an original song. Color denotes a category of derivative
works in the same manner as PlanetView (Fig. 4-(B)).
Above, we describe that Songrium3D visualizes music
structure of a song, derivative works of a song, and othersongs at a time. The important point is that it is not only

Figure 5. Screenshot of the “Songrium3D”. (A) Users cansearch songs using keywords. Similarly, users can search
playlists in Niconico using keywords or a URL. Whenusers choose a Mylist, it starts auto play. (B) It showsa playlist. (C) This spherical object indicates an originalsong. Some objects and ribbons near the song are visual
effects that are synchronized to a song. (D) A song is encompassed with many colorful particles which mean its
derivative works. (E) Other original songs are apparent
way out there. (F) Embedded video player of Niconico forvideo playback and SmartMusicKIOSK for trial listening.

visualizing them at once but also visualizing them seamlessly. Figure 6 shows the transition from the top page to auser-specified song. First, all original VOCALOID songs
are visualized in a three-dimensional space where songs
which sound similar are positioned in proximity, similar
to stars in the cosmos (Fig. 6-(1)). The colors of thesestars correspond to VOCALOID characters, with brightness representing its popularity (number of plays). Whena user chooses a song, a camera starts to move to the song
(Fig. 6-(2)). Users can gradually see more of the song andits derivative works (Fig. 6-(3)(4)). It displays all derivative works of the song as a mass of particles.
After arriving at the song, it displays visual effects thatare synchronized with sounds of the song (Fig. 6-(5)).
Derivative works and other songs are shown in the background when it shows visual effects that can be regarded
as a visualization of the music structure. In this manner,
Songrium3D visualizes all contents seamlessly, which isan important benefit of three-dimensional visualization. It
helps users to be aware of the scale of this music content
creation community.
Songrium3D visualizes music descriptions such as thebeat and music structure, supported by signal processing
and music understanding technologies. Figure 7 shows themanner in which Songrium3D generates visual effects thatare synchronized to a song. Many music players have visual effects that are synchronized to audio signals. However, in the Songrium3D, visual effects can be changed according to the music structure that consists of a chorus andrepeated sections. One visual effect is mapped to one repeated section. Songrium3D has only six patterns of visual effects, but each song has a different music structure.
Then Songrium3D can generate various visual effects thatare synchronized to a song. Handcrafted visual effects canFigure 6. Transition from top page to a user-specified songin Songrium3D. All original VOCALOID songs are visualized in a three-dimensional space. The colors of thesestars correspond to VOCALOID characters, with brightness indicating popularity (number of plays).

represent the deep meaning of a song, but they have highcost.
While there are music visualizers built into existing media players that can show music-synchronized animationof geometric patterns, their music analysis is usually basedon the amplitude or spectrogram of audio signals. Such avisualization approach entails low costs because it can be
fully automatic, but it can represent only the shallow meaning of a song. Our approach is a combination of handcrafted and automated generation. It is entails medium
costs and it can be reflected by the meaning of a song.
5. INTERACTIVE HISTORY PLAYERInteractive History Player visualizes the history of
VOCALOID songs. Figure 8 portrays a screen shot of Interactive History Player. It displays groups of songs published during the specified period in chronological order,
giving the user a full perspective on the trends and transitions in published song groups over time. Each song is represented as a “bubble” (a colored circle). New song bubbles appear in accordance with their respective publisheddates and congregate in an animation (Fig. 8-(A)). The
color of each bubble corresponds to the VOCALOID character, whereas the sizes of the bubbles indicate play counts.
On the left side of the screen, the bar chart presents a summation of play counts of bubbles in the same VOCALOID
characters.
The interface exhibits growth in the music content cre-

Figure 8. Screenshot of the “Interactive History Player” in Songrium. It visualizes the history of VOCALOID songs. (A)A bubble represents the music content. Its size denotes the play counts; its color shows the VOCALOID character. Whenusers click a bubble, its thumbnail and metadata are shown. (B) Users drag and drop a bubble; then the song is added to theplaylist. (C) The timeline displays the current time and popular content in each period. When users click on the timeline, it
jumps to the clicked period. (D) The bar chart shows the summation of play counts of bubbles with the same color. (E) It
displays groups of songs published during the specified period in chronological order, automatically.

Figure 7. Examples of pair of visual effects and repeatedsections. Each visual effect is mapped to a chorus section
or one repeated section. In the left panel, the current timeis repeated for sections 1 and 2. Then users can see a mixof visual effects 1 and 2. Each visual effect will be started
at the beginning of the repeated section.

ation community, arranged by published date, in an animated display. It plays songs for which the play count ishigh in the period automatically. Consequently, this feature enables users to experience a group of songs in one
continuous movie, providing a clear, intuitive picture of
how trends on video-sharing services behave.
Users can play songs with drag-and-drop operations if
users become curious about some songs (Fig. 8-(B)). Additionally, they can change the current time (we called thisfunction “time warp”), and filter songs by VOCALOID
characters solely by mouse operation (Fig. 8-(C)(D)). Furthermore, Songrium enables users to play back the chorus
part using SmartMusicKIOSK. This trial listening environ-Figure 9. Songrium3D on the live stage of Hatsune Miku.
Animation generated by Songrium3D is shown in the gateshaped LED display.

ment makes it easy to ascertain what kinds of songs werebeing published at each time. These interactive functions
help users to browse music contents in a growth community.
The Interactive History Player has two different versions:“Singing derivative works” version and “Dancing derivative works” version. They display derivative works withthe same interface. The bubble colors correspond to their
original songs. A bar chart shows a trend of original songsfor derivative works.
6. EXPERIENCES WITH SONGRIUM
6.1 Songrium on the Web
Users can use all functions of Songrium and can watch
the latest music contents every day merely using the webbrowser. The Songrium web crawler checks updated mu-

6.3 Interactive History Player in public events

Figure 10. Demonstration of Interactive History Player
at a public event. The left panel shows the demo system.
As shown in the right panel, participants are using our service with touch panel display. The wall-hanging big-screen
shows the Interactive History Player screen that is operated
by participants. At the venue, many waiting persons andpassersby watched it.

sic video clips related to VOCALOID on Niconico automatically on a daily basis. The user interface of Songriumis implemented using HTML5, SVG, JavaScript, the
JavaScript library D3.js, threeJS, and the embedded video
player of the Niconico service.
The Songrium service was released to the public at
http://songrium.jp on August 7, 2012. In addition to the
web service, the Songrium extension for Google’s Chromebrowser was released on February 28, 2013. As of April
2015, 128,044 original songs and 564,623 derivative works
had been registered in Songrium. More than 147,000 users
have visited our web site. Of them, more than 2,500 users
have installed the browser extension.
6.2 Songrium3D on the live stage
Animation of Songrium3D was used as a back-screen
movie on the live stage of Hatsune Miku in the “SNOWMIKU 2015 LIVE!” held four times in February 7–8,
2015. It was hosted by Crypton Future Media Inc. for a
total number of audiences of about 7,000.
Figure 9 shows the live performance with Songrium3D.
The centerpiece is a figure of Hatsune Miku on the DILAD
screen and the movie generated by Songrium3D shownover her head. At the bottom, one can see the many lightsticks swung by audience members. The live show used theprerecorded singing voice and prerecorded dancing animations of Hatsune Miku. Only the backup band performed
live on-stage.
We produced a prerecorded animation of Songrium3D toavert problems deriving from internet connections or realtime rendering. We captured screenshots of Songrium3D
in 29.97 fps and combined them to produce a single movie.
A movie of the live performance3 and the animation ofSongrium3D for the live4 are available on the internet.

The Interactive History Player has been used at three big
public events, Niconico Chokaigi 35 , Niconico Chokaigi
20156 and Magical Mirai 2014 in Osaka7 . The first two
were public events for Niconico hosted by Niwango, Inc.
Chokaigi 3 was held April 26–27, 2014, for 124,966 attendees. Similarly, Chokaigi 2015 was held April 25–26,
2015. The total number of attendees was 151,115, up 20%
over the prior year. The last one was a public event for Hatsune Miku hosted by Crypton Future Media, Inc. It washeld in August 30, 2014 for a total number of attendees ofabout 11,000.
Figure 10 presents an image showing the demo system
in Niconico Chokaigi 2015. Many people enjoyed using
the Interactive History Player and watched videos nostalgically. At first, many people were passively browsing contents using the system; then they sought their own memorial contents or period using filtering and the time warp
function. Some users talked about their favored old contents with friends while using our service.
7. RELATED WORK
Songrium, at its core, is a music browsing assistance service. Most previous research into interactive music browsing has emphasized visualization to explore musical collections. A particular visualization technique is often attempted to lay out a music collection in a two-dimensional
plane [8–10] and three-dimensional plane [11–14]. Our
Music Star Map (see Section 3.3) and Songrium3D (seeSection 4) are particular examples of this. Interactive interfaces are also important for user experiences; [15] assists a user in discovering songs. [16] assists a user in finding artists. In contrast to the advances in interactive musicbrowsing described above, Songrium visualizes not only
original songs, but also their derivate works and respective
histories, facilitating the effortless browsing of web-native
music content. Furthermore, we apply our visualization
methods to huge and dynamic volumes of music contents
and release them as a web application.
Music recommendation [17–19] is an automated method
giving users the opportunity to encounter unfamiliar but
potentially interesting songs. Similarly, automatic playlist
generation [20–23] can provide such opportunities forusers. Songrium also assists such user activities by visualizing large amounts of user-generated music content.
However, Celma and Cano report that the collaborative
filtering approach, which is a typical recommendation
method, is prone to popularity bias [24], meaning that atendency by which “The rich get richer” is reinforced bymusic recommendations. It is unsuitable for browsing assistance with large amounts of user-generated music contents. Kamalzadeh reports that 50% of active listeners
would like to choose songs one after another [25]. Furthermore, only 9% use online recommendations and 10% use
shuffle when listening to a collection, which indicates that
5 http://www.chokaigi.jp/2014/abroadEnglish.html

3 https://youtu.be/GOano9x9cBY

6 http://www.chokaigi.jp/2015/abroadEnglish.html

4 https://youtu.be/71o8jit1c4I

7 http://magicalmirai.com/2014/index en.html

active listeners enjoy not only listening to songs but alsochoosing songs. Regarding this point, visualizing large
amounts of user-generated music content can provide an
excellent experience for active listeners, having a complementary relation with music recommendation.
8. CONCLUSIONSAs described in this paper, we proposed two new interfacesof a music browsing assistance service called Songrium,
which visualizes VOCALOID music including original
songs and their derivative works on the video sharing site
Niconico. Our target music content is web-native music:
music content that was born, listened to, and distributed
over the web. Songrium provides various visualization
tools to assist users in grasping the relations among webnative music. Particularly, this paper features Songrium3D,
which portrays to a user all web-native music content in
a community and Interactive History Player, and which
presents a history of related web-native music contents.
As goals for future work, we will continue to run theSongrium service and improve it based on user feedback.
Herein, we described only VOCALOID music, but webnative music is available from many other sources, which
we hope to exploit in the near future.
Acknowledgments
We thank Keisuke Ishida for the web service implementation of Songrium. We also thank anonymous users ofSongrium for editing social annotations. This work was
supported in part by CREST, JST.
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