I've been creating my personal YouTube Music favorites collection, and am up to 300+ songs in it. Any song that I can recall that has outstanding characteristics goes in. The selection is eclectic, ranging through prog rock, show tunes, classical, movie themes, heavy metal, marches, novelty, alternative, etc. When I put it on shuffle play, the sudden change of intensity can lead to aural whiplash. Imagine going from Starless by King Crimson to Mah Na Mah Na by Piero Umiliani to Little Green Apples by Bobby Goldsboro. Just the thing to keep you awake on long drives. I try to keep the song lengths down to six minutes so that any particular genre doesn't get overdone.