clea, camila, and the credits

So I just finished watching this and was glad to see clea duvall and Camila Grey playing in the band... but i'm very confused. The credits don't mention Clea Duvall at all. They mention the lead singer is Sarah Dale. IMDB states that Clea is in IBTC, but plays the part of Laural--though that was played by Jenny Shimizu. Can anyone shed some light on this for me?