It started when I looked up radiohead (88 posts) here as a joke, but looking at another post that had dire_straits (2 posts) I started wondering:
Which band has the most posts here tagged with them?
From my initial cursory search:

pink_floyd (135 posts)
ac/dc (97 posts)
radiohead (88 posts)
weezer (72 posts)
the_beatles (69 nice)
kanye_west (67 posts)
nicki_minaj (49 posts)
david_bowie david_bowie_(artist) (40 posts)
taylor_swift (28 posts)
king_crimson (12 posts)
marshmello (6 posts)
dire_straits (2 posts)

What others am I missing?

sabaton_(band) Has 13
E-rotic has 2
Tism has 68

There’s a whole slew of bands and artists who are featured in posts it might be nigh impossible to list them all

Seems like its probably Nirvana. Here's all the ones I could find with at least 50 posts (I'm probably missing a few):

nirvana (219)
gorillaz (173)
pink_floyd (135)
nine_inch_nails (134)
my_chemical_romance (127)
metallica (101)
ac/dc (97)
caravan_palace (95)
radiohead (88)
daft_punk (82)
slipknot (78)
green_day (76)
weezer (72)
korn (70)
the_beatles (69)
death_grips (68)
tism (68)
kanye_west (67)
iron_maiden_(band) (55)
michael_jackson (53)
linkin_park (52)
kiss_(band) (50)
misfits_(band) (50)

I try to tag musical copyright tags whenever I find it, whether it be lyrics, iconography, or the actual songs in the audio. Here's what I could find.

• Nirvana is the new record at 219!
• My Chemical Romance has 127 uses as of now.
• The Chalkeaters has 101 posts, including some of their animated music videos.
• Metallica has 101 uses.
• Green Day has 76 uses.
• Iron Maiden has 55 uses; that's more than the object at only 41.
• Queen has 41 uses, Freddie Mercury only appearing 10 times.
• Lemon Demon has 37 uses.
• Slayer is used 34 times.
• BlackGryph0n is the original artist for 33 posts, but only the most recent one (post #4327342) has his music.
• Led Zeppelin has only 29 uses. It only had 25 before I posted post #5513209 a week ago, so it's going up.
• Sex Pistols has 26 uses.
• BTS has only 24 uses. e6 is holding out against the K-Pop stans, boys.
• Weird Al Yankovic has 23 uses with only 7 uses as as a character (both dwarfed by the 246 instances of his ponysona).
• Justin Bieber has 22 uses, 15 as a character.
• Twenty One Pilots has 20 uses. Womp womp.
• Guns n' Roses has 18 uses.
• Coldplay has 13 uses.
• Smash Mouth has 13 uses too. Surprisingly, only 3 reference "All Star"'s use in the Shrek franchise.
• Cannibal Corpse has 11 uses.
• The Clash has 10 uses.
• Riot is used 10 times too.
• Death (that's just what it's called...) has 8 uses.
• The Living Tombstone has 6 (maybe 7, I'm not 100% sure if the portion of the remix used in post #5334727 includes some of their work).
• bill wurtz has 4 uses.
• Griffinilla also has 4 uses.
• Willfreedo is yet another with 4. They're a Filipino band MarkOriginals is a part of, discovered while posting his art.
• Kreator has 3 uses
• Pentagram also has 3 uses.
• Alla Pugacheva has 2. She's a Russian musician and I found the lyrics to her "Arlekino" (1975) while posting Maddeku's art. I recommend it if you like clowny music and don't mind Russian lyrics.
• Deicide has 2 uses. What do we tag the killing of a god then?
• Entombed appears twice.
• Frank Sinatra also appears twice, but as a character tag.
• Shadrow also has 2. That's twice what it once was.
• Boston and Ride the Lightning have 1 use on the same post.
• Buzzcocks and Gorgoroth also appear on 1 post in common.
• LilDeuceDeuce has only 1; post #4327342 mentioned above.

Of course, sometimes just a song is tagged. "Caramelldansen" has 223 uses, 48 of which have sound (17 are flash though).

how do we define "band" here? can individual artists be counted here? how fictional can they be before they no longer count?
_{^{(I'm assuming we're not counting stuff like Splatoon's idle groups, like off_the_hook_(splatoon). not only because they're not a real-life band, but also because the tag isn't really used in the same way other band's tags are; just being used to denote when all the members are in a single post and not anything to do with the characters' music/performances.)}}

Nirvana is definitely the right answer. I think most of the IRL band tags on e6 have an entry in album_cover. So many Nirvana, Gorillaz and Weezer covers...

dba_afish said:
how do we define "band" here? can individual artists be counted here? how fictional can they be before they no longer count?
_{^{(I'm assuming we're not counting stuff like Splatoon's idle groups, like off_the_hook_(splatoon). not only because they're not a real-life band, but also because the tag isn't really used in the same way other band's tags are; just being used to denote when all the members are in a single post and not anything to do with the characters' music/performances.)}}

That's a good question! Depending on whether we count them or not so far the answer is either one of the squid bands from splatoon or nirvana based on other answers

discardothediscarded said:
That's a good question! Depending on whether we count them or not so far the answer is either one of the squid bands from splatoon or nirvana based on other answers

I looked through posts containing the Off The Hook members, and I think that, if we tagged off_the_hook closer to how we tag other music groups (music, branding, performances) they'd only have about 40 posts (although my method would've missed posts featuring of the duo's brand/music without them).

and if you want to go in the opposite direction, hatsune_miku has like 1000.

dba_afish said:
how do we define "band" here? can individual artists be counted here? how fictional can they be before they no longer count?
_{^{(I'm assuming we're not counting stuff like Splatoon's idle groups, like off_the_hook_(splatoon). not only because they're not a real-life band, but also because the tag isn't really used in the same way other band's tags are; just being used to denote when all the members are in a single post and not anything to do with the characters' music/performances.)}}

Makes me think of that Pentakill could be the most tagged by counting the members on their own (Kayle, Karthus, Sona, Viego, Olaf, Mordekaiser, Yorick), although it is without the outfits they wear so it probably doesn't count.

dba_afish said:
how do we define "band" here? can individual artists be counted here? how fictional can they be before they no longer count?
_{^{(I'm assuming we're not counting stuff like Splatoon's idle groups, like off_the_hook_(splatoon). not only because they're not a real-life band, but also because the tag isn't really used in the same way other band's tags are; just being used to denote when all the members are in a single post and not anything to do with the characters' music/performances.)}}

dba_afish said:
I looked through posts containing the Off The Hook members, and I think that, if we tagged off_the_hook closer to how we tag other music groups (music, branding, performances) they'd only have about 40 posts (although my method would've missed posts featuring of the duo's brand/music without them).

and if you want to go in the opposite direction, hatsune_miku has like 1000.

You could get really pedantic on what tag is a musician's tag. Dr. Seuss was technically a musician as he wrote the songs for the animated adaptations he was involved with, but the 359 posts are by far about his bibliography than discography. Now that you mention it, Vocaloid is definitely the winner for the most music-related copyright tag, currently at 1333.

Personally, I like that the Squid Sisters, Off The Hook, and Deep Cut tags are used when the gang's all there. I made the Three Brothers of Death tag like that, and I've seen a bit use for twins with duo names. There's "Indigo Marrallang" for Indi Marrallang and Digo Marrallang, but "Glam Sisters" for Glitz and Glam was deleted at some point.

slocheze said:
Personally, I like that the Squid Sisters, Off The Hook, and Deep Cut tags are used when the gang's all there. I made the Three Brothers of Death tag like that, and I've seen a bit use for twins with duo names. There's "Indigo Marrallang" for Indi Marrallang and Digo Marrallang, but "Glam Sisters" for Glitz and Glam was deleted at some point.

the problem with tags working like this is that they function identically to just doing a search with all the characters' names in. I think the tags would be more useful if they could be used as a way to filter for or filter out instances where the characters are doing business as their group, rather than just hanging out off the clock.