Academics from Queen Mary, University of London; King's College London; Oxford University; and the Universities of Indiana and Massachusetts claim to have written the world's first online music recognition software.
The Omras (Online Music Recognition and Searching) project system is the first to let Web surfers find a piece of music in a polyphonic (many sounds at once) symbolic collection using polyphonic audio as a query. In practice, this means that Internet users will be able to retrieve recordings from a full orchestra or a complex piano chord, rather than simply a sound produced by a single instrument or voice.
Computers will also be able to "listen" to a piece of music and then reproduce it in sheet music form. Once a computer has identified and generated the correct sheet music, the applications are infinite. In addition to printing out a score, it will also be possible to synthesise the music on a computer.
PCs will be able retrieve similar pieces of music as well as original or alternative recordings. The new system will find musical variations on one piece. For example, there are at least 12 variations on Twinkle, Twinkle Little Star but if one version is played on a PC, it will find the others.
It will also be possible to buy music online and, in addition to musical archiving, song-sensitive computers will be able to make comparisons between original music and music recorded by songwriters or DJs who lift audio samples from other artists' tracks.
"Systems like ours will change the way we use music in our everyday lives. Being able to get at the underlying musical structure, and then querying online search engines will make music appreciation a much more interactive experience. And for the music industry, it offers new ways to make money," says Mark Sandler, professor at Queen Mary, University of London.
While existing computer systems currently allow music to be identified through an artists' archive, Sandler says in the future we will be able to source music simply by humming a half-remembered chorus or by playing a snippet of music into a PC.
The system works by calculating statistical tables from an existing collection of music, comparing it with the audio input and checking for a match. Part of this process is the automatic transcription of the polyphonic audio into polyphonic symbols. This is an important technique in its own right and is a big step up from monophonic transcription.
The Omras project team includes signal processing scientists, information scientists, musicians, musicologists and librarians. Omras is funded by the Joint Information Systems Committee in the UK and by the National Science Foundation in the US.