Jack's mannequin, Jakalope, Jars of Clay. Jump Steady, Junction 18, Jerk. (Jerk is a band, I'm not calling you one. ;) )
journey
JLS
for Bands that start with a "J". Jodeci,The JB's (James Brown's back up band), Jane's Addiction, The Jam, J J Band, J. Geils Band, Judas Priest, J Punch, J Squad, J Hype, Ja, Ja-Da Quartet, Jack...
Jonas Brothers