All guesses are correct, except Paragon and wolfking did not send Ensiferum.
Evermind: Ensiferum
1: Lai Lai Hei
2: Twilight Tavern
3: Iron
Elite: Agent Fresco
1: Dar_ _a__r
2: D_s_r__r
3: S___o_____ _a_____
4: _o__s
5: Y___o_ N____s
6: S__ ____
Stadler: Rainbow
1: ___ss ____
2: __________ das Na__s__r _a_
3: Anybody ___r_
4: Sno__an
??: __an__ar___ (_a__s __A__s__r, S___an S____ns, N__o ____y, Bry__ D_ssn_r)
1: ______r
2: ____o
3: _ars
??: ___ __a _ar_y
1: __r_ _n ___ __ad
2: ___ Ba_aar (R__as__r_d)
3: _sy__o_o__
4: _a__ar___
??: Black Peaks
1: __ass B____ _as___s
2: Say Yo_ ____
3: _an_ '__ ____
??: _ara_on
1: B_ood __s__
2: _r___
3: S____ra_ _r__nds
Puppies_On_Acid: Darkest Hour
1: A _arado_ ____ ____s - ___ _____
2: ___ __s_ry __ _a__
3: Yo_r ___ry Day D_sas__r
4: __r_ _n ___ S___s
5: _ran____
??: A_o__as
1: Odyss__s
2: _r_os___r_
??: S____ _a_____
1: ___ S_____s - R__as__r_d ____
2: __o__s - ___ An___ o_ _ons - R__as__r_d ____
3: _a___r _n ___ Sand - R__as__r_d ____
4: __ar_s As__nd_n_ - R__as__r_d ____
The Walrus: Broken Bells
1: After the Disco
2: Holding on for Life
3: The Changing Lights
4: Lazy Wonderland
??: ___ __r_
1: _n B_____n Days - ____ R__as__r
2: _____r_s o_ Yo_ - ____ R__as__r
3: _o__son_ - ____ R__as__r
4: A N____ ____ ___s - ____ R__as__r
romdrums: VOLA
1: The Same War
2: Stray the Skies
3: Ruby Pool
4: Still
??: __nd____
1: _r_s_
2: ___ _o_n_a_n (__a_. S____n ___son)
3: ___ _s_and __. _ (Da_n)
4: ___ _s_and __. _ (D_s_)
Sacul: Sufjan Stevens
1: ____a_o
2: John Wayne Gacy, Jr.
3: _o_r__ o_ ___y - ____
4: _oon
Guessed letters: ODBYANRS