I agree it would be platform and type of game dependent.
I only play games / make games for the casual games market and the music is mostly just a background tune - often a very repetitive one. However I usually leave the game sounds on (unless they're annoying) - so you hear clicks / activities - just not the music. All the games I play have the two options - music vs sounds that you can turn on / off separately. I write all my games similarly.