unique Ringtones

I don't even know if this is possible... Also, after Adam's lecture I think it might be annoying...
But nonetheless, I want assign a musical note to each digit (0-9), so whenever someone calls you, the program will read their phone# and convert it to a song.
This way, everyone will have their personalized, unique ringer.
I don't know if that kind of access (reading incoming calls' numbers) is even possible.