Unrealistic expectations

A reader on Macintouch asks,

I have one daughter who likes to make up songs and another who would like to accompany her on a couple of different instruments. Unfortunately, neither one is old enough or experienced enough to be able to easily figure out the notes or chords of the made-up song.

I thought I saw, some time ago, a piece of software that claimed to be able to 'listen' to music played or sung and create notation. It doesn't have to be particularly accurate, just close enough to give a starting point.

It also would be nice if it were affordable but I would entertain any and all suggestions.

So someone expects the computer to listen to a live performance mix of a song by amateur musicians, filter out the separate instruments, and isolate, notate, and analyze each melody line? This falls under the category of "artificial intelligence", which does not exist yet. I know there are digital MIDI interfaces for guitars, but I doubt software exists which can turn a strum into "G7+9" or "Bbmaj7".

My suggestion is: don't be a cheapskate, and pay for some music theory lessons for your daughter!

UPDATE: Ian Coleman emailed me and pointed out Intelliscore Polyphonic. While at first glance this proves me wrong, I recommend reading the FAQ page and seeing all the caveats. I suspect that Intelliscore would have enormous amounts of trouble with such things as modulation. (Geekable readers are welcome to purchase me a copy of Intelliscore Polyphonic so I can test my predictions.)