Crazy Comets is a very simple shoot 'em up game for the Commodore 64, apparently based on the arcade game 'Mad Planets'.
I encountered the game around 1987 in the immense game collection of my cousin's Commodore 64, which I had been able to borrow for a few weeks while he was on a holiday. I wasn't so much impressed with the game itself, but I immediately fell for the music. It's just incredible what has been achieved here with just 3 sound channels and one noise channel.
Although I have no C64 myself, I am able to listen to the music any time I want using one of the many Commodore 64 emulators around. I like to use CCS64, but C64S is a good one as well. The best result however is obtained by using SidPlay or SidAmp, special C64 emulators that comcentrate solely on the Commodore 64 sound chip. Do not use PC64 to hear Crazy Comets, the sound is inadequate.
There are also midi files, MOD files and extended MOD files of Crazy Comets around, but it just isn't the same. Take for example the modulated block wave that was used as bass, or all the little sound effects. It is just unsurpassable.