OK, I’ll confess: I do not play any musical instruments, nor have I spent even an hour of my life ever studying music. Therefore — take this playlist title with a grain of salt. These are songs that sound like they feature xylophones (in reality, much of what’s played here might be from a synthesizer, a glockenspiel or a marimba) or some of these cowbells may not really be cowbells (the extent of my knowledge here is the Saturday Night Live skit).
Having provided that disclaimer, I will say that for runners these two instruments (or things that sound like them) provide a nice accompaniment for a run. One keeps a clanking beat, associated with rock anthems, and the other provides a brighter “ting-ting-ting” tune to lighten tired legs.