Casual fans and folks who want to get introduced to X should first get 'Make The Music Go Bang'. That compilation serves up a 2-CD slice of some of their biggest songs and serves as a proper Greatest Hits package.'Beyond & Back' is served better as a complimentary collection to 'Make The Music Go Bang' by delving further into the X catalog with rarities, outtakes, B-Sides, and alternate takes on some of their greatest songs.Together, 'Make the Music Go Bang' and 'Beyond & Back' makes a nice 4 disc set that covers much ground over X's illustrious career.