"Summer (Where Do We Begin?)" is a song from the movie Phineas and Ferb The Movie: Across the 2nd Dimension. It is performed by Phineas and Ferb with a sense of enthusiasm as their attempt to demonstrate the joys of summer vacation to their second dimension counterparts. This song is included as the 7th song in the Phineas and Ferb: Across the 1st and 2nd Dimensions album and it was sung also by Baljeet, Buford and Isabella in "Fly On the Wall" and was voted #5 on Phineas and Ferb Musical Cliptastic Countdown Hosted by Kelly Osbourne.