Mobile Networked Music Demonstration: Sequencer404
Travis Thatcher*, David Jimisont, John Goetzingert Jason Freeman* and Gil Weinberg*
*Music Technology Group, Georgia Tech
Travis.Thatcher@gatech.edu, gilw@gatech.edu, jason.freeman@gatech.edu
tDigital Media, Georgia Institute of Technology
David.Jimison@gmail.com, John.Goetzinger@gatech.edu
Abstract
This paper describes the demonstration of an application
for multi-user control of a musical sequencer through
telephony and Voice Over Internet Protocol (VOIP).
Participants phone into a central server and through the use
of the numeric buttons of their device, control the rhythm
and pitch of their selected instruments, collaboratively
generating a musical composition.
1 Introduction
Sequencer404 is a collaborative, networked music
system in which users phone in using any type of touchtone
telephone device (payphone, cell, landline) and are able to
create musical compositions. The heart of the system is the
server-side sequencer that is based off of a simple 16-step
pattern sequencer of the type commonly found on drum
machines from the 1980's (ex: Roland TR-808). Each user
is assigned an instrument to control and each receives the
audio generated by all users in the group. Sequencer404
enables networked musical collaboration amongst mobile
non-collocated groups, building upon existing multi-user
musical interfaces and networks [1, 2]. Unlike the desktop
computer paradigm, our system leverages users' mobility
and their local sound environment, exploring issues relating
to Weinberg's notion of synchronous centralized networks
[3] and musical collaborating using limited input channels.
2 Software and Control
The software system we have created for
Sequencer404 utilizes Skype for VOIP connections with the
users to perform DTMF recognition for control of the
sequencer. It also handles the communication between
Skype clients and the server program, currently
implemented in MAX/MSP.
We have created four instruments for users to
choose from: bass synth, FM lead synth, drum machine, and
sampler. Each instrument works in a similarly, with the
phone keys '1-9' mapped to a sound or note depending on
the instrument. The '0' key is used to erase the pattern and
the '#' serves as a tap tempo control that effects the entire
system. The sampler is unique in that it allows users to
sample from their physical environment and map the sounds
chromatically to their keys, stressing the mobile aspect of
Sequencer404.
3 Aesthetics
Sequencer404 embraces the low fidelity audio
quality of phones in its aural palette. These compositions
are intended as expressions that explore these limitations,
where too many simultaneous sounds distort into noise.
Sharing sound through invisible networks, as participants
wander through various physical spaces, investigates
collaborative presence and emphasizes the mobile aspects of
such a network. As opposed to collocated collaboration, the
medium becomes the singular mode for interacting and
communicating. This interplays with the physical
environment of the participant, which informs their input to
the group.
4 Future Work
Future improvements and features that we will have
implemented for ICMC2006 include building a J2ME client
for cell phones that will work with the existing audio
system. We are also investigating more musically
interesting methods of control, using voice pitch detection
for both the pitch control as well as for control of higher
level musical features. Novice users can benefit from the
simplistic system currently in place, however adding control
for rhythmic stability and melodic contour in more
advanced user modes will provide a more engaging
experience for advanced users and musicians.
References
Burke, P. 2000. Jammin' on the Web - a New Client/Server
Architecture for Multi-User Musical Performance. In
Proceedings of the International Computer Music Conference.
Ramakrishnan, C., Freeman, J., Varik, K. 2004 The Architecture
of Auracle: a Real-Time, Distributed, Collaborative
Instrument. In Proceedings ofNIME 2004.
Weinberg, Gil. 2005. Interconnected Musical Networks: Toward a
Theoretical Framework. Computer Music Journal 29(2), 23 -39, Summer 2005.
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