Earlier today, Kendrick Lamar appeared to tease a new release via Instagram. Just now, he’s released “The Heart Part 4,” a new song. It’s available over at iTunes, though it doesn’t yet appear to be streaming. Kendrick’s last major release was last year’s untitled unmastered. “The Heart Part 4″ follows previous “The Heart” songs in his catalog. Update (9:49 a.m.): The song began streaming earlier this morning; find it below.