okies now ill agree, my memory is refreshed and games like Settlers III and IV and Warcraft II (DAMNIT THIS MUSIC ROCKS) and many more realy enchance the game. and yes, it cannot break the game - as you can easily turn it off.
still, after a while i turn the music down and plug in something of mine - for example Warcraft II is forever associated with Abba in my memory
but i have
all warcraft II music in midi on my pc, i even ocassionaly put it on... (rarely tho).