Noah was kind enough to point out The "Unh!" Project. It illustrates and provides commentary on various instances of guttural comic book noises. ("UKH!", "ARGGGH!", "MMNNH!", "UNNGHH!", and more.)
Seems like the same thing should be done for musical grunts and soulful interjections, complete with audio clips. (Think James Brown's "Ow!", or Michael Jackson's "Daggonit!") Are you up to the task, Kan?