Plot: Swept up in a holiday mood, Alvin gives away his cherished harmonica to a sick little boy. Meanwhile, Dave has booked Alvin to perform a harmonica solo at Carnegie Hall! Alvin keeps the loss of his harmonica a secret from Dave, and with the help of Simon and Theodore scrambles to earn enough money to buy another harmonica in time for his Carnegie Hall debut! Along the way you'll hear Alvin, Simon and Theodore getting ready for the Big Night, singing their own comical version of the holiday favorites like "Jingle Bells," "Deck the Halls," and their famous "Chipmunk Song (Christmas Don't Be Late)