From HMXHenry on rockband.com:

Hey gang,

Not only are three epic artists joining RB for the first time next week, but they've got Pro mode covered in spades! There are epic harmonies for The Bee Gees, keys galore for A Whiter Shade of Pale (give it a listen, I bet you'll recognize it) and you couldn't ask for a better Pro guitar teacher than B.B. King. Enjoy!

Available on Xbox 360, Wii and PlayStation 3 system (Nov. 16):

Bee Gees – “Jive Talkin’”
Bee Gees – “Night Fever”
Bee Gees – “Stayin’ Alive” X
Bee Gees – “Nights on Broadway”
Bee Gees – “Tragedy”
Bee Gees – “You Should Be Dancing”
B.B. King – “The Thrill Is Gone” X
Procol Harum – “A Whiter Shade of Pale”

(All tracks are original master recordings)
(These tracks will be available in Europe on PlayStation 3 system Nov. 17)

These tracks will be available for purchase as individual tracks, as well as “The Bee Gees Pack 01” on Xbox 360, PlayStation 3 system and Wii. Tracks marked with “X” will include Pro Guitar and Pro Bass expansions for $0.99 per song.

Price:
$1.99 USD, £.99 UK, €1.49 EU (160 Microsoft Points) per song
$2.00 USD (200 Wii Points™) per song
$0.99 USD (100 Wii Points/80 Microsoft Points), £0.59 UK, €0.75 EU per song for eligible Pro Guitar/Pro Bass upgrade
$9.99, £4.99 UK, €7.99 EU (800 Microsoft Points, 1,000 Wii Points) for The Bee Gees Pack 01

** Dates for Rock Band game tracks are tentative and subject to change. **

How RB3 didn't feature B.B. King is baffling to me.
 
All of the Bee Gees and B.B. King for me. Jesus Harmonix, you're throwing everything you've got at us lately.

Alright! B.B. King's comin' out for my birthday? Paaaarrrrr-taaaaaay. 
 
God I'm lame. Ha.

Damn, now that's what I call some must-have DLC. I was afraid after last week that HMX was going to start a trend of re-releasing old DLC with keyboard/guitar upgrades. 

Stayin' Alive is a must have!

Whiter Shade of Pale is one of my all time favourites and it's so good to keyboard and sing on there.