In a totally kickass move, Harmonix has announced that it will release the entirety of Megadeth’s “Peace Sells – But Who’s Buying?” album as well as a 4-pack in honor of the concert tour promoting Rock Band 2.

The following tracks from the album will be available collectively for 880 Microsoft points ($11) or individually for 160 points ($2).

• Wake Up Dead
• The Conjuring
• Devil’s Island
• Good Mourning / Black Friday
• Bad Omen
• I Ain’t Superstitious
• My Last Words

The missing title track can be found on the Rock Band 2 disc which will be released tomorrow on Xbox 360.

The 4-pack features bands on the concert tour. The tracks can be bought collectively for 320 Microsoft points ($4) or individually for 80 points ($1).

• “One of Those Nights” by the Cab
• “Hands Down” by Dashboard Confessional
• “She’s a Handsome Woman” by Panic At the Disco
• “Natural Disaster” by Plain White T’s

These songs will be available on Xbox Live Marketplace starting Tuesday, September 16; PS3 users get them two days later.