"The Substitute" includes cover versions of six songs. Paltrow performs on four of these. She recorded them all in one day. The songs she recorded were "Conjunction Junction" from Schoolhouse Rock!, and a clean version of Cee Lo Green's "Fuck You!" entitled "Forget You". The producers of the series had wanted Paltrow to sing a Coldplay song. They chose to not do this. They wanted to use the song for a competition episode of "Glee". Morrison and Shum, Jr. sang a duet version of "Make 'Em Laugh" from the musical "Singin' in the Rain". Paltrow and Michele did a duet on "Nowadays / Hot Honey Rag" from the musical "Chicago". Morrison and Paltrow performed a mash-up of "Singin' in the Rain" with "Umbrella" by Rihanna featuring Jay-Z. The cast had to spend twelve hours filming for the mash-up in a tank of water.