Reach the indicated rank to unlock the corresponding bonus episode:

ABC by The Jackson 5: King Of The Beat (sixth rank)
Believe by Cher: Captain Of Soul (fourth rank)
Survivor by Destiny's Child: Legendary Agent (ninth rank)

Successfully complete Crusin' mode to unlock Sweatin' mode.

Successfully complete Sweatin' mode to unlock Hard ROCK! mode.

Successfully complete all songs in every mode (Breesin, Crusin, Sweatin, Hard Rock!) to replace Elite Beat Divas's leader with Commander Kahn.

Unlock Hard ROCK! mode to unlock Mr. X in single-card and multi-card Vs. mode instead of Commander Kahn. Note: If Commander Kahn is unlocked, he will replace Mr. X.

Reach the highest rank to view a congratulatory picture, which will also become unlocked in the gallery.

Successfully complete the final song (Jumpin' Jack Flash) on the "Hard ROCK!" difficulty setting to unlock the "Credits" on the bottom right corner of the Gallery screen.