As obligatory as the greatest-hits package and tribute record for the retiring veteran artist is the rarities compilation for new artists moving from the underground to mainstream record-buying consciousness. That said, Let It Happen, a collection of B-sides recorded by MxPx for Tooth and Nail Records before the band was signed away to A&M, comes off as a much stronger record than a simple attempt to cash in on a departing band. And, given that it contains 32 songs--clocking in at nearly 72 minutes--the value is certainly good, too. But the real strength of the CD lies in the short, aggressive, and unbelievably catchy pop-punk tunes MxPx churned out in spades. The songs they relegated as B-side material actually make for one of MxPx's more satisfying albums. And though these songs come from many different sessions stretched out over three years, the disc is surprisingly cohesive, thanks in no small part to new mixes by longtime MxPx producer Steve Kravac, whose sonic fairy dusting gives these tracks a Hüsker Dü-like roar. --Bradley S. Caviness