Lady Gaga was one of a number of stars to perform for a crowd of some 150,000 New Year's Eve, as Dick Clark and co-host Ryan Seacrest counted down to midnight at the annual "Dick Clark's Rockin' Eve" special, televised on ABC.  Gaga performed a medley of songs for the upbeat crowd, then joined New York Mayor Michael Bloomberg in starting the descent of the iconic Times Square ball that symbolizes the beginning of a new year.  Checik out Gaga's musical performance below.  Other performers on the night included Justin Bieber, Carlos Santana, Cee Lo Green.