Lady Gaga and Stevie Wonder teamed to sing Wonder's "Happy Birthday" to Elton John at the rock legend's 70^th birthday party in Los Angeles on Saturday.

Gaga and Wonder served up a duet of the Hotter Than July track, with Gaga occasionally modifying the lyrics from "Happy birthday to you" to "Happy birthday Elton" for the occasion.

John's 70^th birthday bash at Red Studios was a star-studded affair with a guest list that included Gaga, Wonder, Katy Perry, Jon Hamm, and many more.