http://www.jhu.edu/~allnight/ All-male group. http://www.jhu.edu/~ketzev/ Ketzev is a coed Jewish a cappella group that features songs in a variety of languages including Hebrew, Yiddish, and English. http://jhunix.hcf.jhu.edu/~mental/ Coed a cappella with a pop sensibility and a generous dollop of humor. Sound clips in RealAudio and MP3 formats. http://jhuniverse.hcf.jhu.edu/~sirens/ All-female group with a pop repertoire stretching from 60s to 90s. http://www.jhu.edu/%7evchords/ Coed group with a varied repertoire of pop and traditional songs. Lots of photos and biographies.