The be all end all of music mods

If you've ever heard of the Ambience mod, Music Triggers is Ambience after it chews 5 gum. It allows creating a full soundtrack for your modpack through a host of custom rules you can build in the config files, and it is the most advanced music player ever made for MC (no music is included, this is a dev tool for playing sound files based on conditions you add to the folder). The recent updates also sort of bundled the functionality of travelers titles into the mod, which is neat. And the rules you can specify can be ridiculously specific. Like only playing a given song while under water, at night, inside a cave, in biome X. If you ever wanted to add a dynamic soundtrack to your pack like triple A games have, this is the mod to do it.