I can imagine something like this happening: The basic outline for a song can be varied randomly - infinitely for all practical purposes - and the results checked against the parameters that are used to define music. So it could be that we would only rule out that which is known to violate the basic rules - that known to assault the senses. The rest passes as new styles, melodies, etc.zoobyshoe said:New songs in a pre-existing style already exists (see Hypnagogue's link). New styles would take some very creative leap to figure out. The way the program analyzes old Chopin to write new Chopin turns out to be: take alot of his old music apart into pieces and reassemble the pieces in a new configuration. This is fine for a limited number of "new" compositions, but I bet after a while it would become horribly repetitive. In real life a composer evolves, abandons old habits and discovers new things to explore.
However, we are talking about creations and not reproductions, which strikes at the heart of the topic. How does one spontaneously create something with a mathematical structure? And what makes it a work of genius, say for example, as compared to one of my tunes.If you immerse yourself in something all the time it becomes habitual. After listening to Bach for a few hours I start to hear Bach-like music in my head and sometimes can't stop this for a couple days. I think it is just a matter of inertia: get a whole bunch of neurons working on a certain kind of thing and they'll continue at it even when you're not pushing them to do so anymore.
And what about lyrics? Could a computer write poetry; and then poetry that mates with a melody in a "meaningful" way?