Lady Gaga made a surprise appearance during Elton John's free show in West Hollywood on Saturday. Gaga, who is godmother to Elton's two children, joined her great friend on stage for a beautiful performance of his 1974 hit "Don't Let the Sun Go Down on Me."

"This great man has inspired generations with his powerful music and warm heart there will never be another like him and there never was before," Gaga told fans after performing with Elton. "His uniqueness is compounded by his ability to love endlessly while also creating the biggest hits the world has ever known."

The concert was organized as a thank you to the City of West Hollywood for their support of the Elton John AIDS Foundation and streamed live on AOL.com.

Lady Gaga is set to perform at the Oscars tomorrow, February 28th.