[ Ray Finch wrote in 040608 MMDigest:


>> Being that nowadays music is rarely recorded to a true [analog]
>> "sound recording" (this being vinyl or analog tape) and today
>> is almost always in a digital format,


This overlooks the essential difference between sound recordings,
digital or analogue, and formats such as piano rolls.  Piano rolls
(and MIDI files) record a set of instructions for synthesising the
sounds rather than the sounds themselves.  A digital recording is
a representation of the actual sound.  I admit that compression
techniques are starting to blur the differences.

This is not true of MP3 and other common bit rate reduction systems,
though future compression systems could work by sending instructions
for synthesis.  Even the venerable vocoder achieved its great
compression partly by this sort of technique.

Jeffrey Borinsky

 [ Like the punched cards that controlled the Jacquard loom, piano
 [ rolls and MIDI files store commands (to push down a piano key).
 [ Such data files are not computer programs because the host machine
 [ lacks a key attribute: the ability to alter the set of commands
 [ based upon the state of the machine.  Thus we say the MIDI data
 [ file is executed (played) by a MIDI player program, just as a
 [ piano roll is executed by a roll-playing machine at the piano.
 [
 [ Some pianists treat printed sheet music as instructions to be
 [ faithfully executed, but others (like jazz performers) alter the
 [ instruction set during performance depending on their interaction
 [ with other musicians, audience feedback, mood, etc.  Certainly
 [ the "pianolist" controlling the expression of the player piano
 [ can add much to an otherwise mechanical sounding performance.
 [ -- Robbie