What was the last song in the mamma mia movie?

The first and last song in the movie itself is I Have a Dream. However the credits open with the cast performing Dancing Queen and then Waterloo in spandex and platform boots. (The stage play ends the same way.) The final ABBA song that plays under the credits is Thank You for the Music, performed simply by Amanda Seyfreid with ABBA's Benny Andersson on the piano.