In a tree farm, three musically inclined chipmunks, Alvin(Justin Long), Simon(Matthew Gray Gubler) and Theodore(Jesse McCartney), find their tree cut down and sent to Los Angeles. Once there, they meet the frustrated songwriter David Seville, and despite a poor house wrecking first impression, they impress him with their singing talent. Seeing the opportunity for success, both human and chipmunks make a pact for them to sing his songs. While that ambition proves a frustrating struggle with the difficult trio, the dream does come true after all. However, that success presents its own trials as their unscrupulous record executive, Ian Hawke(David Cross), plans to break up this family to exploit the boys. Can Dave(Jason Lee) and the Chipmunks discover what they really value amid the superficial glamor around them?