Bruce Springsteen is “The Boss,” but not when it comes to the “Harry Potter” movie franchise. Bruce Springsteen sat down for an interview with the BBC and he revealed that he wrote a song for a “Harry Potter” movie but it was rejected. According to the Boss the song is titled “I’ll Stand By You.” He said he was inspired to write the song after reading the Harry Potter books to his son. Bruce describes the song as a “big ballad that was very uncharacteristic” of what he would normally sing himself. t is believed that Harry Potter’s author, JK Rowling, has a contract preventing the use of commercial songs in Harry Potter movies.