A head's-up: Steve Smith, a Philosophy/Religious Studies guy at Millsaps College, has a blog/chronicle/study of hooks, specifically hooks in rock songs. Smith's project is off to a fine start, and while I admit that our definitions of "hook" differ, it still makes for enjoyable and thought-provoking reading. Just to explain the difference: my idea of a hook has always been an instrumental riff that grabs you by the collar (or something else) and doesn't let go—ever. Obvious examples would be the the opening electric piano lick from "Summer in the City" (Lovin' Spoonful), the closing piano lick from Paul McCartney's "Venus and Mars," the signature guitar licksfrom the Beatles' "Day Tripper" (yes, Clapton did it first in the Bluesbreakers' version of Ray Charles's "What'd I Say," but still), Sugarloaf's "Don't Call Us, We'll Call You," the Byrds' version of "Mr. Tambourine Man," the Move's "Do Ya" (much superior to ELO's), etc. You know what I mean, right? It's a hook!