Chains on Me is a song that is played when Phineas and Ferb are in the Smile Away Reformatory School. ("Phineas and Ferb Get Busted/At Last"). It shows how the Sergeant is forcing all of the children to abandon their imagination and creativity, with Phineas and Ferb receiving the most indoctrination since they have the most of both.
Even though he wasn't involved with Phineas and Ferb's invention for that day, Phineas and Ferb's friend, Baljeet was in Smile Away Reformatory School as well. The only reason Baljeet was in the Smile Away Reformatory School because he got kicked out of summer school (his grades were "too high").
In Spanish, the title of the song is "Mis Cadenas Son" (My Chains Are).