> Have you never seen sheet music? That is what Shannon was estimating - > the bitrate for describing music in the abstract. There are a finite > number of notes, durations and amplitudes in a classical composition. > > I suspect 40 bits/sec is still far too tight, but a midi stream using a > high end reconstruction codec represents a pretty good example of what > is possible by way of compression for *music* as opposed to voice or a > random noise stream.
Which is why we are talking about midi. Recording SOUND is a different thing. Note that a cymbal crash is very close to white noise. This means that exact reproduction allows for little compression. Of course all music is not cymbal crashes (or usually so) which is where MP3 comes from.
> Be interesting if the reference to this paper can be found to see how he > allocated those 40 bits/s.... > > I reckon at a bare minimum about 7 to the note, 8 to amplitude, 6 > duration, 5 to the instrument - and it is already obvious that you > cannot encode more than a single note per second at this bitrate.
Sorry NOT "obvious". You need to learn more about information theory! Note that you have encoded ONE note but looking at sheet music one observed that MANY notes are identical! Hence there is redundancy that can be eliminated for compression.