Proceedings of the 18th International Congress on Acoustics (ICA 2004), pp.I-553-556, April 2004. (Invited Paper)

Development of the RWC Music Database
Masataka Goto
National Institute of Advanced Industrial Science and Technology (AIST)
m.goto@aist.go.jp

Abstract
In this paper I introduce the RWC (Real World Computing) Music Database, a copyright-cleared music database(DB) that is available to researchers as a common foundation for research. Shared DBs are common in otherresearch fields and have made significant contributions
to progress in those fields. The field of music information processing, however, has lacked a common DB ofmusical pieces or a large-scale DB of musical instrument
sounds. The RWC Music Database was therefore built as
the world’s first large-scale music DB compiled specifically for research purposes. It contains six original component DBs: the Popular Music Database, Royalty-FreeMusic Database, Classical Music Database, Jazz Music
Database, Music Genre Database, and Musical Instrument Sound Database. The DB has been distributed toresearchers at a nominal cost to cover only duplication,
shipping, and handling charges (i.e., it is practically free),and has already been widely used.

1. Introduction
I believe that research into music information processing
will be advanced if music databases (DBs) are available
that can be used by various researchers. The main purposes and advantages of such commonly available DBs
can be summarized as follows:• Researchers will be able to use the DBs as a common benchmark for comparing and evaluating various methods related to music information processing. The lack of common music DBs available
worldwide for research purposes at almost no costhas made it difficult to establish benchmarks (evaluation frameworks) for much of the research done
regarding music information processing.
• The DBs will stimulate research in corpus-oriented
approaches that use statistical methods and learningtechniques. Recent progress in the use of statistical methods in other research fields such as speech
recognition has been largely due to the availabilityof large DBs.
• Researchers will be able to use the DBs for research
publications and presentations without conventional
copyright restrictions. It has been difficult to demon-Mo5.H.3

strate research using copyrighted musical pieces thatwill be included in, for example, conference videos
and CD-ROMs.
Although there is an enormous amount of music available on commercially distributed compact discs aroundthe world, it is difficult to use this music for the above
purposes because of copyright restrictions. Commonly
available DBs with copyright-cleared pieces are therefore
essential to encourage the healthy development of this research field.
Various commonly available DBs have been built inother research fields such as speech and image processing
since the importance and significance of such DBs havebeen widely recognized. The field of music information
processing, however, has long lacked a copyright-cleared
DB of musical pieces that can be used as a common foundation for research. For musical instrument sounds, there
are the McGill University Master Samples [1] and theUniversity of Iowa Musical Instrument Samples [2] released for public use, and private collections assembled
within companies [3]. Nevertheless, there has still been aneed for a large-scale common DB containing the soundsof many musical instruments played in various styles.
I therefore organized the RWC Music Database SubWorking Group (chair: Masataka Goto) in the Real World
Computing Partnership (RWCP) of Japan and constructedin fiscal 2000 and 2001 a music DB — the RWC (RealWorld Computing) Music Database [4, 5] — that researchers can obtain and use freely in common for research purposes. The RWC Music Database features
six component DBs: the Popular Music Database (100pieces), Royalty-Free Music Database (15 pieces), Classical Music Database (50 pieces), Jazz Music Database(50 pieces), Music Genre Database (100 pieces), and Musical Instrument Sound Database (50 instruments). For
all 315 musical pieces performed and recorded for the DB,
we prepared original audio signals, corresponding standard MIDI files, and text files of lyrics (for songs). For
the 50 instruments, we captured individual sounds at halftone intervals with several variations. of playing styles,dynamics, instrument manufacturers, and musicians. The
following sections describe the design policy of the RWCMusic Database and then explain the specifications ofeach of the six DBs.

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Table 1: List of music compact discs (CDs) and DVD-ROMs for distributing the RWC Music Database.
Content (Version)
Popular Music Database (Original Version: Mixed)
ditto (Karaoke Version and Vocal-only Version: Separate)
Royalty-Free Music Database (Original Version: Mixed)
ditto (Karaoke Version and Vocal-only Version: Separate)
Classical Music Database (Original Version: Mixed)
Jazz Music Database (Original Version: Mixed)
Music Genre Database (Original Version: Mixed)
Musical Instrument Sound Database (Wave Files)

Quantity
7 CDs
14 CDs
1 CD
1 CD
6 CDs
4 CDs
9 CDs
12 DVDs

CD/DVD Catalog Number
RWC-MDB-P-2001-M01 ∼ M07
RWC-MDB-P-2001-S01 ∼ S14
RWC-MDB-R-2001-M01
RWC-MDB-R-2001-S01
RWC-MDB-C-2001-M01 ∼ M06
RWC-MDB-J-2001-M01 ∼ M04
RWC-MDB-G-2001-M01 ∼ M09
RWC-MDB-I-2001-W01 ∼ W12

Piece/Inst. Nos.
Nos. 1–100
Nos. 1–100
Nos. 1–15
Nos. 1–15
Nos. 1–50
Nos. 1–50
Nos. 1–100
Nos. 01–50

Catalog number: RWC-MDB-[Content]-[Year]-[Version][Volume No.], Content, Version: The underlined letter, Year: Made in 2001

2. Design policy
The RWC Music Database Sub-Working Group had toaddress various design, trade-off, and copyright issues inbuilding the RWC Music Database. In this section, I summarize the most important issues.
2.1. Content
We decided to include musical instrument sounds as wellas musical pieces.
With respect to musical pieces, an ideal DB would
contain many richly varied musical pieces, in various genres, of the highest quality possible. For practical purposes, though, we had to build our DB under production resource constraints such as our budget and available time. We therefore took up three major music genres — popular, classical, and jazz — and constructed
the Popular Music Database, Classical Music Database,and Jazz Music Database. Moreover, we constructed
the Royalty-Free Music Database to provide well-known
popular songs and the Music Genre Database to provide
a variety of genres. We tried to include as many realisticpieces as possible in a way that reflected the complexityand diversity of real-world music. For example, as wellas ensuring that various styles, moods, tempi, and lengths
were represented, we also included as many professional
composers, lyric writers, arrangers, singers, and players
as our resources allowed.
With respect to musical instrument sounds, we constructed the Musical Instrument Sound Database covering 50 musical instruments and, for each instrument,
recorded individual sounds at half-tone intervals. Furthermore, to provide variety in playing style, dynamics (stress), instrument manufacturers, and musicians, wemade many recordings for each type of instrument.
2.2. Copyrights of musical pieces
To make our DB available to researchers around theworld, we had to obtain all the necessary copyrights andassociated legal interests related to this DB.1 We there1 Note that our DB is not copyright-free even though it is available

for free for research purposes: we reserve all necessary copyrights andneighboring rights. All users of the DB must submit the user agreement

fore included 315 pieces (for the five component DBs)
that were all newly performed, sung, and recorded for the
purpose of inclusion in the DB. For the Popular Music
Database, we included 100 pieces that were originallycomposed and arranged in modern popular music styles(the lyrics were also originally written). For the RoyaltyFree Music Database, we included 15 public-domain
traditional popular-music pieces that were originally arranged for this DB. For the Classical Music Database,we selected 50 well-known public-domain pieces. For
the Jazz Music Database, we included 50 pieces wherefour well-known public-domain pieces were originally arranged and the other 46 pieces were originally composed
and arranged. For the Music Genre Database, we included 100 pieces where 27 public-domain pieces wereselected for some music genres (classical, marches, vocals, and some traditional Japanese music) and the other73 were originally composed and arranged.
2.3. Standard MIDI files (SMFs) and lyrics text files
We prepared transcribed SMFs for all 315 pieces. These
were stored in SMF format 1 (multiple tracks) and conform to the GS format. Given the corresponding audio
signals, most of them were transcribed by ear. These
SMFs are valuable because they can be freely used forresearch purposes and can also be used as effective substitutes for scores. Song lyrics are provided as separate
text files.
2.4. Audio signals before mixdown
In addition to the original audio signals after mixdown,
we obtained audio signals of all the tracks before mixdown, which are usually not available on commerciallydistributed compact discs. Since each track generally corresponds to a different instrument’s part, the audio signalsof each part can be studied.2To obtain this valuable information, the processes ofrecording, mixdown, and mastering (including masteringeffects) were done on Pro Tools (Digidesign, Inc.), a proform to the general manager of the RWC Music Database.
2 This correspondence was not always possible for live-recording
pieces in the classical and jazz music genres because several parts weresometimes mixed within a single track.

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data made it possible to browse all the tracks and to mix
them down with different mixing balances.
2.5. Distribution media
We used music compact discs (CD-DA: stereo, 16 bit /44.1 kHz) as the medium for distributing the audio signalsof musical pieces. Each piece is provided as an “Original Version” that was mixed just as a producer originallyintended. For the Popular Music Database and RoyaltyFree Music Database, we also prepared music compact
discs containing both a “Karaoke Version” that mutes thevocal part of the original version and a “Vocal-only Version” that records only the vocal part. On the other hand,
we used DVD-ROM discs as the medium for distributing
the Musical Instrument Sound Database. The recorded
sounds of this DB are provided as monaural sound files at
16 bit / 44.1 kHz in the RIFF WAVE format.
Table 1 lists the music compact discs and DVDROMs. Each of the musical pieces and musical instruments has a unique “piece/instrument number” (sequential within each DB) that should be referred to for research
use and publication (e.g., RWC-MDB-P-2001 No. 28).

3. Six component databases
The following subsections provide an overview of the six
component DBs [4, 5].
3.1. Popular Music Database
This DB consists of 100 songs — 20 songs with English lyrics performed in the style of popular music typical of songs on the American hit charts in the 1980s, and80 songs with Japanese lyrics performed in the style ofmodern Japanese popular music typical of songs on theJapanese hit charts in the 1990s. All 100 songs with vocals were originally produced in as rich a variety as ourresources allowed. As a result of our attempts to achievea good male-female balance in the 100 songs and to include songs by vocal groups, there are 50 songs by 15
male singers, 44 songs by 13 female singers, and 6 songsby 6 vocal groups.
3.2. Royalty-Free Music Database
This DB consists of 15 songs, 10 well-known standard
popular songs with English lyrics and 5 well-known children’s songs with Japanese lyrics. All 15 public-domain
songs were originally arranged and recorded for our DB.
This DB was built to provide well-known popular songs,
while the Popular Music Database contains only original
popular songs.
3.3. Classical Music Database
This DB consists of 50 pieces:• Symphony: 4 • Concerto: 2 • Orchestral: 4• Chamber: 10 • Solo: 24• Vocal: 6
All 50 public-domain pieces were originally recorded forour DB. These pieces were selected to represent a richvariety of instrumentation, style, period, composer, andmood. We did not intend to produce a mere anthology
of well-known musical pieces: we tried to include pieces
that have been previously used in research or have interesting aspects from a research viewpoint.
3.4. Jazz Music Database
This DB consists of 50 pieces:• Instrumentation variations: 35 pieces(5 pieces × 7 instrumentations)• Style variations: 9 pieces• Fusion (crossover): 6 pieces
All 50 pieces were originally produced for our DB, except for the composition and lyric writing of four stylevariation pieces. First, the instrumentation-variation
pieces were recorded to obtain different versions of thesame piece; i.e., different arrangements performed by different player instrumentations. Five standard-style jazzpieces were originally composed and then performed inmodern-jazz style using seven instrumentations: 1) piano solo, 2) guitar solo, 3) duo (vibraphone + piano, flute+ piano, or piano + bass), 4) piano trio, 5) piano trio +trumpet or tenor saxophone, 6) octet (piano trio + guitar+ alto saxophone + baritone saxophone + two tenor saxophones), and 7) piano trio + vibraphone or flute. Second, the style-variation pieces were recorded to represent
various styles of jazz. The nine pieces, which include
four well-known public-domain pieces, consist of vocal
jazz (two), big band jazz (two), modal jazz (two), funky
jazz (two), and free jazz (one) pieces. Finally, the fusion
pieces were recorded to obtain music that combines elements of jazz with other styles such as popular, rock, andLatin. They include music with an eighth-note feel, musicwith a sixteenth-note feel, and Latin-flavored music.
3.5. Music Genre Database
This DB consists of 100 musical pieces, three for each of
33 genres and one for a cappella. It is divided into 10 maincategories (popular, rock, dance, jazz, Latin, classical,
marches, world, vocals, and traditional Japanese music)
and 33 subcategories (popular, ballads, rock, heavy metal,rap/hip-hop, house, techno, funk, soul/R&B, big band,
modern Jazz, fusion, bossa nova, samba, reggae, tango,baroque, classic, romantic, modern, brass band, blues,
folk, country, gospel, African, Indian, flamenco, chanson,canzone, traditional-style Japanese popular music Enka,
Japanese folk music Min’you, and ancient Japanese court
music Gagaku). Note that this does not mean to imply
that all music can be categorized in this way: these categories were used simply for convenience when record-I - 555

ing the pieces. All 100 pieces are original recordings, 73
being original compositions and 27 being existing publicdomain pieces.

Table 2: Number of orders for each component database of theRWC Music Database as of December 12, 2003.
Component database
Popular & Royalty-Free Music Database
Classical Music Database
Jazz Music Database
Music Genre Database
Musical Instrument Sound Database
Total number

3.6. Musical Instrument Sound Database
This DB covers 50 musical instruments and provides, inprinciple, three variations for each instrument. It thus
comprises performances of about 150 instrument bodies.
To provide a wide variety of sounds, we took the following approach.
• Variations (3 instrument manufacturers, 3 musicians): Each variation featured, in principle, an instrument from a different manufacturer played by adifferent musician.
• Playing style (instrument dependent): Within therange possible for each instrument, we recorded
many playing styles.
• Pitch (total range): For each playing style, the musician played individual sounds at half-tone intervals
over the entire range of tones that could be producedby that instrument.
• Dynamics (3 dynamic levels): We also recorded
each playing style at three levels of dynamics (forte,mezzo, piano) spanning the total range of the instrument.
In producing RWC-MDB-I-2001 No. 01 “Piano”, forexample, we used three pianos from three different manufacturers and recorded, for each of 88 keys, four different playing styles (normal, staccato, pedal, and repeatedplaying of the same sound) at three dynamic levels (forte,mezzo, and piano). In other words, we recorded a totalof 3168 (3 × 88 × 4 × 3) individual sounds for this DB
item. These sounds were assembled into 36 (3 × 4 × 3)
files, each holding 88 keys’ worth of sounds.
The sounds of these 50 instruments were stored in3544 monaural sound files having a total size of about
29.1 Gbytes and a total playback time (including muteintervals) of about 91.6 hours. Each file, in principle,
holds a collection of individual sounds in the order of ascending pitch across the total range of an instrument. Inaddition, about five color photographs of each individual
instrument were also taken and assembled into 948 files(about 703.1 Mbytes).

4. Conclusion
I have introduced the RWC Music Database containing
the six original component DBs. This DB is available
to researchers around the world at a nominal cost tocover only duplication, shipping, and handling charges(i.e., it is practically free). It is possible to access information on obtaining the DB by entering “RWC Music Database” in any WWW search engine. As shownin Table 2, it has already been widely used in various research themes, including, but not limited to, music un-Organizations
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derstanding, music structure analysis, musical instrument
analysis/identification, sound source segregation, noise
reduction, music information retrieval, and music-relatedvisualization. With this DB, researchers can now use
copyright-cleared musical pieces and musical instrument
sounds for each stage of problem finding, problem solution, implementation, evaluation, and presentation.
In the future, it will be necessary to add various metadata (descriptions of contents) to the DB pieces throughcooperation with several research institutes. We hope that
our DB will be widely used worldwide, and that various
other DBs for music information processing will follow,
thus accelerating progress in this field of research.

5. Acknowledgments
I thank everyone who has made this DB project possible.
The members of the RWC Music Database Sub-Working
Group — Hiroki Hashiguchi, Takuichi Nishimura, andRyuichi Oka — devotedly helped to build this DB. I
received considerable cooperation from Yuzuru Hiraga,
Keiji Hirata, Satoru Hayamizu, Hideki Asoh, Katunobu
Itou, Roger Dannenberg, Alain de Cheveigné, and Dan
Ellis. This project was supported by many parties involved in the RWC project. The C MUSIC Corporation
carried out the production of all the musical pieces andthe recording of the instrument sounds.

6. References[1] Frank Opolko and Joel Wapnick, “McGill university mastersamples (CDs),” 1987.
[2] Lawrence Fritts, “University of Iowa musical instrument
samples,” http://theremin.music.uiowa.edu/MIS.html.
[3] Kunio Kashino and Hiroshi Murase, “A sound source identification system for ensemble music based on template
adaptation and music stream extraction,” Speech Communication, 27(3–4):337–349, 1999.
[4] Masataka Goto, Hiroki Hashiguchi, Takuichi Nishimura,and Ryuichi Oka, “RWC music database: Popular, classical, and jazz music databases,” In Proc. of ISMIR 2002,
pp. 287–288, 2002.
[5] Masataka Goto, Hiroki Hashiguchi, Takuichi Nishimura,and Ryuichi Oka, “RWC music database: Music genredatabase and musical instrument sound database,” In Proc.
of ISMIR 2003, pp. 229–230, 2003.

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