Rock: generic term
Rock-N-Roll: from the 50s to early 60s
Classic Rock: Mid 60s to 70s
Progressive Rock: mostly 70s and later, long, complex songs in weird time signatures (7/11, 10/6)
Folk Rock: Acoustic, folk lyrics
Alternative Rock: early 90s on, maybe late 80s
Punk Rock: roughly 1975 on, musical style should be obvious.
mp3 tags have strange genres, including many that seem to only exist in mp3 tags.
Heh. How about New Romantic, Ska/Rock, Post-Rock, Post-Metal…
(respectively, an early 1980’s precursor to “alternative,” what it says on the tin, long-form instrumental like Mogwai, and the latter with more metal influences)
It’s all labeling, & pretty arbitrary I have to suppose.
Since *you *are the one doing the tagging, and presumably *you *are the one who will do the searching by tags later, it only makes sense to use whatever definition feels right to you.
A lot of labels come about when white kids from, say, England try unsuccessfully to imitate Black musicians from elsewhere. Punk rhythms are rooted in Reggae and Ska, as played by working-class English guys who didn’t quite understand the patterns involved. Metal began as English guys who wanted to play like Jimi Hendrix, with limited success. Techno/Industrial was a conscious effort to get away from Rock’s Blues origins and play something more European (i.e. Kraftwerk). Who’s playing and who they’re trying to sound like are vital to identifying the genre.
At various times, Rock has had a left wing and a right wing until a specific artist or movement brought them together (Mods and Rockers clashed, until the Beatles blurred the boundaries; Hair Metal and Alt.Rock defined much of late 80s music, until Nirvana and other Seattle bands used elements of both).