When hard-working songwriter Dave Seville (Jason Lee) meets a trio of talented chipmunks - Alvin, Simon and Theodore - he immediately recognizes their talent and the trio become musical sensations overnight. But a greedy producer (David Cross) is determined to take advantage of the three "young men" and sends them on a grueling concert tour just to line his own pockets. Can Dave use a little human ingenuity - and a good dose of chipmunk scheming - to save his charges before it's too late?