Ain't It Funny (feat. Ja Rule & Cadillac Tah) - Murder Remix

This was co-written by Jennifer Lopez and Cory Rooney for the 2001 Adam Shankman-directed romantic comedy The Wedding Planner. Cory Rooney recalled to Songwriter Universe: "Jennifer and I were in Canada, and we wanted to write a song [which was originally intended] for her movie, The Wedding Planner. The music popped in my head, and I went home and worked on the track. Then I sat with Jennifer and we banged out the song." "Tommy (Mottola) was even involved with writing the song," Rooney added. "He was so enthusiastic about the track, that he contributed melody ideas to the song."

Adam Shankman felt that the song had too much of a Latin influence to be featured in The Wedding Singer. However, the song was included on Lopez's second studio album J.Lo. Released as its third single on June 20, 2001, it was a commercial success, peaking within the top ten in multiple countries, though it didn't originally chart on the Hot 100.

Sales of the song were boosted by a remix by Irv Gotti and 7 with additional vocals from Ja Rule and Caddillac Tah. The remix peaked at #1 on the Hot 100 and Airplay for the week ending March 9, 2002 giving Lopez her third chart-topper following "If You Had My Love" and "I'm Real."