The Client Music Synthesis (CMS) is a technology conceived to transfer very large music files via internet (or via any communication means having similar data transmission characteristics). It allows an extremely compressed format, far more compact than, for example, mp3. The sound quality is fair, provided that it is intended for some specific purposes, such as music study or training. MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding and lossy compression format and algorithm, designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. ...

For example, choir training aids (4 parts) of Requiem KV626 by W.A. Mozart require 13 CD of uncompressed audio files, corresponding to some 6 GB of data. The same files, compressed by mp3, may require 200 to 1000 MB, depending on the sound quality (the minimum may be acceptable for training purposes, the maximum is close to hi-fi). With CMS, the same data are compressed as only 2 or 3 MB, with a compression ratio of 2000 - 3000 as opposed to 7 - 40 of mp3.

A CMS file is an executable file transferred from a server to a client. The CMS file includes 4 mandatory element sets:

1) a software sound synthesizer;

2) a set of sound samples;

3) a set of files containing music data in a very concise format (e.g., MIDI, MusicXML, etc.); Musical Instrument Digital Interface, or MIDI, is a system designed to transmit information between electronic musical instruments. ... MusicXML is an open, XML-based music notation file format. ...

4) a set of automatic procedures that instruct the software sound synthesizer to create audio files corresponding to the music data, using the sound samples included.

Optionally, the CMS file may contain additional files, such as CD covers to be printed, lyrics, training suggestions, etc. .

The set of sound samples is made in such a way that it only contains the sound types required for the specific music included in the CMS file. This dramatically reduces the size of the set of sound samples, while the quality of the synthesized sound may be very good, if high quality samples are used.

By running a CMS file, the automatic procedures are activated, that in turn invoke the software sound synthesizer so that the music data are transformed into actual sounds by means of the sound samples included. CD-quality audio files are thus created locally on the client. The name "Client Music Synthesis" summarises the described process.

The inventor of the CMS technology decided not to patent it, and the principles of such a technology were released on the public domain for free use. Its original application was the distribution of free training aids for choirs.

External links

• Choralia - web site distributing free training aids for choirs, based on CMS technology