Original songs on "21 Hits"

"Crazy Horses" was covered by The Meatmen on the album "Toilet Slave"

"Crazy Horses" was covered by Tank on the album "Power of the Hunter"

"Crazy Horses" was covered by Glam Metal Detectives on the album "Everybody Up!"

"Crazy Horses" was covered by Throat on the album "Knievel Is Evil"

"Crazy Horses" was covered by La Muerte on the album "Experiment in Terror"

"Double Lovin'" was covered by Baha Men on the album "The Best Of Baha Men"

Cover songs on "21 Hits"

The Frankie Valli song "I Can't Live a Dream" was originally on the album "Closeup"

The Frankie Valli song "The Proud One" was originally on the album "Frankie Valli"