A - Andrew Byrd
B - The Beatles
C - Chumbawamba
D - Dire Strates
E - Enrique Granados (Classical piano)
F - For In Hand
G - Green Day
H - Harry Chapin
I - Idil Biret
J - Jonathan Coulton
K - King Crimson
L - Lyle Lovett
M - Minutemen
N - New Pornographers
O - Oscar Peterson
P - Polyphonic Spree
Q - Queen
R - Rush
S - Stevie Ray Vaughan
T - Turtle Island String Quartet
U - Ultramagnetic MC's
V - Velvet Revolver
W - Wynton Marsalis
X - I can't think of anything that starts with X so I'll put Planet X
Y - Yngwie Malmsteen
Z - Zappa

A - Asking Alexandria
B - Bob Marley
C - Colt Ford
D - Disturbed
E - Eminem
F - Foo Fighters
G - Guns N' Roses
H - Hollywood Undead
I - Isis
J - Johnny Cash
K - Kottonmouth Kings
L - Lynyrd Skynyrd
M - Metallica
N - Nirvana
O - Oasis
P - Pastor Troy
Q - Queen
R - Rage Against The Machine
S - Steve Miller Band
T - Three Days Grace
U - U2
V - Van Halen
W - Whitesnake
X - XTC
Z - ZZ Top

A - Arctic Monkeys
B - Bloc Party
C - Calvin Harris
D - Darwin Deez
E - Enter Shikari
F - Foals
G - Green Day
H - Hoosiers, The
I - ----
J - J Majik
K - Kooks, The
L - Lonely Island, The
M - Midnight Beast, The
N - ----
O - OneRepublic
P - Panic! At The Disco
Q - Queen
R - ----
S - Streets, The
T - Two Door Cinema Club
U - ----
V - ----
W - Wombats, The
X - ----
Y - You Me At Six
Z - Zutons, The

A- Agraceful
B- Before Their Eyes
C- Confide
D- A Day To Remember
E- Emmure
F- Finch
G- Greeley Estates
H- Hopes Die Last
I- Ice Nine Kills
J- Jamies Elsewhere
K- Karate High School
L- Lovehatehero
M- Miss May I
N- ---
O- Of Machines
P- Parkway Drive
Q- ---
R- ---
S- The Sound Of Animals Fighting
T- Thursday
U- The Used
V- Vienna Falls
W- Woe Is Me
X- ---
Y- ---
Z- ---

A - Autechre
B - Boards Of Canada
C - Clark
D - Don Caballero
E - Extra Life
F - **** Buttons
G - Godspeed You! Black Emperor
H - HEALTH
I - If These Trees Could Talk
J - Jackson And His Computer Band
K - Kayo Dot
L - Lightning Bolt
M - maudlin of the Well
N - NEU!
O - Oxbow
P - Portishead
Q - ??????????????
R - Radian
S - Sunn O)))
T - Toby Driver
U - Ulver
V - VHS Head
W - Wu-Tang Clan
X - XTC
Y - Yowie
Z - Zs

A - April Wine
B - Black Sabbath
C - Camel
D - Def leppard
E - Earth, Wind and Fire
F - Foo Fighters
G - Greatful Dead
H - Hawkwind
I - Iron Maiden
J - Jon & Vangelis
K - Kinks
L - Little Feat
M - Marillion
O - Osibisa
P - Porcupine Tree
Q - Queen
R - R.E.M.
S - Styx
T - Tangerine Dream
U - Utopia
V - Van Der Graff Generator
W - Wishing Tree
X - nada - I have an X Ray Spex single but haven't played it in ages.
Y - Y & T.
Z - Zappa, Frank.

Can't believe I never attempted this, guess I was afraid

A - At the Drive-In
B - Blood Brothers, The
C - Camille
D - Dillinger Escape Plan, The
E - Eyedea & Abilities
F - Fall of Troy, The
G - Guster
H - Honeycut
I - Iron Maiden
J - Jeff Buckley
K - Kings of Leon, for the old stuff
L - Led Zeppelin
M - Mars Volta, The
N - Number Twelve Looks Like You, The
O - OutKast
P - Protest the Hero
Q - Queen
R - Radiohead
S - Smiths, The
T - Tubelord
U -
V - Velvet Underground, The
W - Weezer for the first two albums alone
X - XTC
Y - You Slut
Z -

EDIT: Anyone missing an X needs to get English Settlement by XTC, pronto

A: A Whisper in the Noise
B: B.B. King
C: Cat Stevens
D: Django Reinhardt
E: Echo and the Bunnymen
F: Fleet Foxes
G: Godspeed You! Black Emperor
H: The Heavy
I: Isaac Albeniz
J: Jimi Hendrix
K:
L: Led Zeppelin
M: Madvillain
N: The Nightwatchman
O: Okkervil River
P: Public Enemy
Q: Queens of the Stoneage
R: Rory Gallagher
S: Son House
T: Television
U: The United States of America
V: The Velvet Underground
W: White Denim
X: Xiu Xiu
Y: The Yardbirds
Z: Zach de la Rocha

A - Avett Brothers
B - Blockhead
C - Cake
D - David Bowie or Dusty Springfield
E - Everclear
F - Flogging Molly
G - Gogol Bordello
H - Heart (don't judge me :hphones: )
I - Iggy and the Stooges
J - Johnny Cash (I suppose I should put Jimi here to fit in :rofl: )
K - Kyuss
L - Led Zeppelin
M - Mexican Institute of Sound
N - Nick Cave (Grinderman OR Bad Seeds, doesn't matter :D )
O - Outlaws
P - Presidents of the USA
Q - Queens of the Stone Age
R - Reverend Horton Heat
S - Supergrass
T - A Tribe Called Quest
U - U2
V - Van Morrison
W - Wyclef Jean
No X :wavey:
Y - Yello
Z - Zero 7

:D

I'll give this a try.

A-The Avalanches
B-Boredoms
C-The Clash(C has loads of good bands though, cool letter)
D-Deftones
E-Exuma
F-Faust
G-The Germs
H-Husker Du
I-I Hate Myself
J-Jefferson Airplane
K-The Kinks
L-Low
M-Melvins
N-The National
O-Outkast
P-Pixies
Q-Quicksilver
R-The Replacements/Ride
S-Slowdive
T-Television/Thelonious Monk
U-Ulver
V-The Velvet Underground
W-The Who
X-X
Y-Young Marble Giants
Z-The Zombies
#-16 Horsepower