Web technology based pieces driven by operation
data transmitted from audience's smartphones
Kita Toshihiro
http://tkita.net
BackgroundA merely perfect live performance of an electronic piece does not necessarily
give 'live' impression due to the high (sometimes too high) degree ofabstraction in electronic instrument performance (e.g., just one pressing of abutton plays a complete portion of a tune).
Excellent expression of a performer is possible if the instruments used in theperformance are elaborate enough, and it can give the audience a feeling of'live'. Another possibility of letting audience feel it live is to allow theaudience to participate in the piece in real time.
Recent penetration of smartphones has made audience participation in live
electronics pieces easily possible. The author of this article has published apiece utilizing the data from the audience to a computer for sound generation
as well as and a revised version of the piece that additionally includes thefeedback from the computer to the audience devices.

I. First piece at Csound Conference 2013
The piece "Audience's Smartphone Jam Session" [1] that was played atCsound Conference 2013 in Boston is consisted of the data transmitted fromaudience by using their own smartphones or tablets in the concert venue inreal time.
The system for the piece uses a WiFi router for accepting connection fromeach participant, and a Linux laptop that runs Csound and lighttpd. It uses
only the local network and needs no Internet connection.
What participants have to do is to find the WiFi access point, connect theirsmartphones to it and go to the Web page where they can specify andtransmit x-y data by touching a rectangle area. By performing asynchronousJavaScript data transmissions from the smartphone browsers, OSC (OpenSound Control) messages are generated by a PHP script to control Csound[2].

csoundLinuxlaptop

lighttpd + php

WiFirouter

Web browsers onsmartphones etc.

AndOSCapp

Fig. 1 System configuration for the pieceII. Revised version of the piece at WAC2014
The revised version of the piece released at Csound Conference 2013 wasperformed at WAC2014 [3] in Paris. The revised piece is accompanied withaudio feedback to audience. The system was revised to include soundgeneration by HTML5 Web Audio API at each participant's smartphone
individually. The volume of the smarphone sound is controllable on theLinux laptop. All the smartphones at a time, or selected one or twosmartphones can be separately controlled via a Web browser. Using thisconfiguration, a piece for and by audience is able to be performed if many ofthem have smartphones or some Wifi-enabled devices with them at the venue[4].

csoundLinuxlaptop

lighttpd + php

WiFirouter

Web browsers on
smartphones etc.

Feedback for volume controlof Web Audio API soundAndOSCapp

Fig. 2 System configuration for the revised pieceReferences[1] Kita Toshihiro, “Audience's Smartphone Jam Session (excerpt)” atConcert6, 2nd International Csound Conference, Boston, October 27th, 2013.
http://www.youtube.com/watch?v=J12iOcZkI6I[2] System configuration for ”Audience's Smartphone Jam Session”, anaudience-driven interactive piece requiring no dedicated apps, Publication ofJapanese Society for Sonic Art, Vol.5 No.3, pp.12–14 (2013.12)
http://data.jssa.info/paper/2013v05n03/3.Kita.pdf[3] Kita Toshihiro, "Smartphone Jam Session with Audience" at Web Audio
Gigs #2, 1st Web Audio Conference (WAC2014, http://wac.ircam.fr/ ), Paris,
January 27, 2015
http://wac.ircam.fr/program.html[4] “EMSAN/JSSA Day 2015 5th Presentation Toshihiro KITA, in Gifu,
Japan, September 11th, 2015.
https://www.youtube.com/watch?v=fACZKhsxXZ0