the singer from Hootie and the Blowfish was from Gaithersburg :dontknow: haha ummm... Joan Jett moved to Rockville (right down the road) when she was in High School or Junior High. obviously neither of those are really part of the local scene anymore. oh, and R.E.M. wrote "(Don't Go Back To) Rockville" about the area, too.
SR-71 is one of my favorite bands of all time, and they're from the Baltimore / Towson area. if you've heard the song "1984" (and trust me, you have) then you've enjoyed some SR-71 goodness (even though Bowling For Soup are the ones who put the single out the singer from SR-71 wrote it and they recorded a better less radio-friendly version).
Frank Zappa was born in Baltimore. thats got to count for some serious points. then Good Charlotte takes some points away, i guess. O.A.R. is pretty neutral in the points running i would think. apparently Tupak moved to Baltimore in High School too. gotta love Wikipedia.
otherwise this area is pretty typical. lots of crappy bands, and a very select few that turn out to be decent. but in an area like this it's hard to decide what to call "local." MD isn't huge, so Baltimore, DC, northern VA, and anywhere in between can really be called local.