American Bandstand. December 12, 1964. If you take notice, at 1:12-1:14, that's Freddie Cannon in the audience who is laughing and gives Neil a wave.
From original Album Neil Sedaka - Happy Birthday - Sweet Sixteen.
Happy Birthday Sweet Sixteen by Neil Sedaka from the album Happy Days - 75 Classics Sounds from the Rock 'N' Roll Years Released 2014-05-23 on One ...