Ruin a band by removing one letter from its name.
I’ll go first…
Oxy Music
Cunt’s 77
The Cript
The Grateful Dad
Had no idea who they were…had to reverse engineer. 
The Ho
Young whippersnappers from the 2000s…
Talking Heds (apparently they are Scottish).
Rolling Tones (have a big following in Yorkshire).
The Doos
Cunting Crows
Cunting Cows
It’s two letters, but I hate bovines
Red Ho Chili Peppers
U2
didn’t even need to remove a letter to make them ruinous.
The Cur
Feetwood Mac
The th Dimension
The Onkees
Canned Hat
Ten Ears After
Ream
Kind of an improvement 
Le Zeppelin (French metal band)
Lack Sabbat
The Each Boys
Too much rumination.