Yes, duplicate. Sorry, the search function didn't bring that one up, only another ticket that was marked as solved in 2014.
@klugemonkey: This is definitely also affecting singleplayer.
Seems to affect block entities, e.g. chests, anvils, switches, etc., but not blocks. Doors and trapdoors are fine. Also affects picking up items. Teleportation results in "rubberbanding". Also seems to affect the generation of certain chests in ruins and shipwrecks, they're generated empty. Furthermore affects the pointer on maps updating its position.
Seems to affect creative mode more than survival mode, and it affects switching gamemodes too.
And it affects monsters. A creeper just moved to an old position where I was several seconds ago, exploded and the explosion hurt me, even though I was about fifteen blocks away. Same with skeletons shooting at former positions and hitting me. Also affects crossbows.
Next function affected: Falling damage and Elytra.
Screenshot for visualization
Played the current snapshot for an hour, could not replicate.
Can confirm this bug for Snapshot 14w03b, happens exactly as described. Two songs overlap and even setting the music volume to 0% can't stop them from starting again after a few seconds.
Can confirm this bug, happens exactly as described here: Two songs overlap and even setting the music volume to 0% can't stop them from starting again after a few seconds..
Seed for 21w06a: 5864409455779207650