Computer app allows classical musicians to perform solo with virtual accompaniment

May 13, 2014

Musicians can now perform as the soloist with a full philharmonic orchestra from the comfort of their own living rooms, thanks to a new computer system that will be described in a presentation at the 167th meeting of the Acoustical Society of America, to be held May 5-9 in Providence, Rhode Island.

"Classical musicians spend untold hours learning to play the solo literature featuring their instrument, but very few ever perform this music with the accompanying ensemble. The reason is it takes many players to make an orchestra, but only one to be a soloist," said Christopher Raphael, chair of Computer Science in the School of Informatics and Computing at Indiana University, Bloomington, and a former professional oboist. "While the oboe is not the favorite solo instrument of composers or audiences, I have performed as a soloist 10 or 15 times. The experience was thrilling, so I wanted to find a way to replicate the feeling of this experience, and to share it with others," he said.

"I have worked on this for many years," Raphael added, "since it represents a kind a grand challenge—bringing together an application domain I care deeply about, and some areas of in which I have expertise."

In , or, for that matter, in any ensemble performance, each musician must form ongoing predictions about the way the music will evolve and continually revise these predictions based on what they hear. To emulate this process with a computer model, Raphael developed a so-called Bayesian Belief Network, which is "a simple model for musical timing that understands the nominal note values from the score and what they imply about duration, and the way tempo changes fluidly in a performance," he explained.

This video is not supported by your browser at this time.
Video Showing how Info Phil Works

To model the hearing of the accompanists—and thus be able to identify, and respond to, the notes played by the soloist, and when they occur—the system uses an algorithm known as a hidden Markov model, which is commonly employed in speech-recognition technologies.

The simulated orchestra is synthesized from a prerecorded orchestra, which means there is no limit to the number of instruments involved, "though it isn't always easy to find a recording of a concerto minus the soloist," Raphael says.

The system—which Raphael has dubbed the "Informatics Philharmonic"—is designed to understand the "imprecise nature" of humans, and, like an artificial intelligence system, can learn to adapt to the soloist's interpretation of the music. The model can be automatically trained from past performances (and must be trained for each individual soloist), "thus capturing the essence of the human rehearsal process in which one learns from example," he said.

Technically, he added, the program has a score of the piece that gives the basic information of the score, more or less as it is presented in the score: pitches and rhythmic values. This is the information that is used to "hear" the soloist. To create the accompaniment, the program uses a prerecorded accompaniment performance that is matched to the symbolic score offline, which allows the accompaniment to be played back while its timing is warped so that it synchronizes with the soloist.

Explore further: In blind test, soloists like new violins over old (Update)

More information: Free app for Mac: itunes.apple.com/us/app/cadenz… -follows/id525322035

Provided by Acoustical Society of America

4.7 /5 (3 votes)
add to favorites email to friend print save as pdf

Related Stories

Musicians take note of tune-writing app

May 06, 2013

Need some instant musical notation to remember that little tune you just came up with? A new mobile app created by a researcher from KTH Royal Institute of Technology makes it possible to score any melody ...

Global orchestra gives classics a modern stage

Mar 28, 2011

Classical violinist Paolo Calligopoulos says he pulled on the leather jacket, black fedora and sunglasses to perform an electric guitar solo for an online audition just for fun.

Recommended for you

Gamers' funding fuels meteoric rise of 'Star Citizen'

11 hours ago

Chris Roberts' brain spun out a grand vision: a rich, immersive galaxy; exquisite spaceships traversing between infinite star systems with thousands of computer gamers manning the cockpits, racing, dogfighting and defending ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

winthrom
not rated yet May 13, 2014
Music minus one (registered trademark) with tempo control.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.