Actually when I am playing singlepayer I find it pretty cool, especially the chosen music for the nether and the end, it really gives the gameplay this tone in the background that makes you feel in a different way more into your surroundings. Most of the time when I'm hardcore gaming I just put on my own music, which is normally techno/dubstep.
Minecraft music is awesome when it's actually peaceful. It becomes annoying when I play a heated game of OITC and it suddenly plays Calm. I try to change the settings=spawn killed.