The sound of people flipping through CD cases fills the room at this gigantic new and used music emporium. A gaping maw of a store, Sonic Boom doesn’t give much thought to the shopping experience: when you want to listen to a CD, your keys or ID are demanded as hostages. But the daily arrival of approximately 1,500 CDs, records and DVDs is enough to keep people coming. Used CDs range from $3.95 to $10.95; DVDs cost as little as $5.95 and rarely top $40, even for television series. CanCon devotees should check out the bin of local artists, most of whom sell on consignment. A healthy contingen of new releases ($16.99–$20.99) is also sold.