Frail, from Philadelphia, were one of the first screamo bands to make a huge impact on the scene. Straightedge and into animal rights, the band was political as well. If you are used to todays sound, this will sound like crap but worth your time if you want to hear where Adam from Taking Back Sunday, At-The Drive In, etc. all stole from for their shows. If you find their discography, "Make Your Own Noise", definitely buy/download it.
One of their best songs, "Firecracker". At about 2:14 in, check out the emo breakdown.
Frail's UnOfficial MySpace Page
Unofficial Page which also has some audio samples.