The future of music recording
| A computer model of the clarinet was built A virtual player for the virtual clarinet was created |
Humans can manipulate their tongue, breath, and fingers only so fast, so in theory recorders shouldn’t really have to measure the music many thousands of times a second like it is done on a CD.
As a result, researchers may have found the absolute least amount of data needed to reproduce a piece of music.
The researchers at the University of Rochester have digitally reproduced music in a file nearly 1,000 times smaller than a regular MP3 file.
Two innovationsThe music, a 20-second clarinet solo, is encoded in less than a single kilobyte, and is made possible by two innovations: recreating in a computer both the real-world physics of a clarinet and the physics of a clarinet player.
In replaying the music, a computer literally reproduces the original performance based on everything it knows about clarinets and clarinet playing. Two of Mark Bocko (professor of electrical and computer engineering and co-creator of the technology)’s doctoral students, Xiaoxiao Dong and Mark Sterling, worked with Bocko to measure every aspect of a clarinet that affects its sound — from the backpressure in the mouthpiece for every different fingering, to the way sound radiates from the instrument, according to a University of Rochester press release.
They then built a computer model of the clarinet, and the result is a virtual instrument built entirely from the real-world acoustical measurements. The team then set about creating a virtual player for the virtual clarinet. They modelled how a clarinet player interacts with the instrument including the fingerings, the force of breath, and the pressure of the player’s lips to determine how they would affect the response of the virtual clarinet.
Then, says Bocko, it’s a matter of letting the computer “listen” to a real clarinet performance to infer and record the various actions required to create a specific sound. The original sound is then reproduced by feeding the record of the player’s actions back into the computer model.
Including ‘tonguing’“We are still working on including ‘tonguing,’ or how the player strikes the reed with the tongue to start notes in staccato passages,” says Bocko. “But in music with more sustained and connected notes the method works quite well and it’s difficult to tell the synthesized sound from the original.”
At present the results are a very close, though not yet a perfect, representation of the original sound. Bocko believes that the quality will continue to improve as the acoustic measurements and the resulting synthesis algorithms become more accurate, and he says this process may represent the maximum possible data compression of music.
More intuitive waysAs the method is refined the researchers imagine that it may give computer musicians more intuitive ways to create expressive music by including the actions of a virtual musician in computer synthesizers.
And although the human vocal tract is highly complex, Bocko says the method may in principle be extended to vocals as well.
The current method handles only a single instrument at a time.
However in other work in the University’s Music Research Lab with post-doctoral researcher Gordana Velikic and Dave Headlam, professor of music theory at the University of Rochester’s Eastman School of Music, the team has produced a method of separating multiple instruments in a mix so the two methods can be combined to produce a very compact recording.
