Four song titles from 2x07 on Amazon!

Nowadays/Hot Honey Rag (Chicago) - Gwyneth Paltrow (and possibly Lea.)
http://www.amazon.com/Nowadays-Version-featuring-Gwyneth-Paltrow/dp/B004B4N9FE/ref=sr_1_1?ie=UTF8&qid=1289150988&sr=1-1

Singing in the Rain/Umbrella (Rihanna) - Gwyneth Paltrow with the club + Matt.
http://www.amazon.com/Singing-Umbrella-Version-featuring-Gwyneth/dp/B004B4P1SM/ref=sr_1_2?ie=UTF8&qid=1289150988&sr=1-2

Forget You - Gwyneth Paltrow (and possibly more people.)
http://www.amazon.com/Forget-Version-featuring-Gwyneth-Paltrow/dp/B004B4N9M2/ref=sr_1_3?ie=UTF8&qid=1289150988&sr=1-3

Make 'Em Laugh (Singing in the Rain) - ?
http://www.amazon.com/Make-Laugh-Glee-Cast-Version/dp/B004B4N9TU/ref=sr_1_4?ie=UTF8&qid=1289150988&sr=1-4

via gleeclub