ckd | Spot the patterns (fun music quiz, NOT politics/epidemiology/etc)

I hate that I had to put that disclaimer up there.

What do the following sets (and sets of sets) of musical artists have in common?

A.
1. Natalie Merchant, k.d. lang, The Flaming Lips
2. Annie Lennox, Seal, Victoria Williams & The Williams Brothers
3. Pearl Jam, Big Country, Bon Jovi
4. Tori Amos, Willie Nelson, Johnny Cash

B.
1. Everything but the Girl, Bob Seger & The Silver Bullet Band, Mary Chapin Carpenter[, Rod Stewart]
2. Marc Cohn, Hootie and the Blowfish, 10,000 Maniacs
3. Sarah McLachlan, Allison Moorer & Shelby Lynne, Richie Havens[, The Eagles]

C.
1. Joseph Arthur, Don Ho, Ben Neill featuring Andrew Montgomery
2. Erasure, Sarah McLachlan, Lou Reed
3. Dave Matthews Band, Supreme Beat featuring Dave Wakeling, Jamie Woon

D. [Bob Dylan (answered by

bibliophile)]
1. Edie Brickell & New Bohemians, Jason Mraz, Ann Wilson
2. Thea Gilmore, Indigo Girls, XTC[, Jimi Hendrix]
3. My Chemical Romance, Robyn Hitchcock, Grateful Dead
4. Mungo Jerry, Warren Zevon, Avril Lavigne
5. Crowded House, Duane Eddy, Frankie Valli & The Four Seasons[, William Shatner]
6. Great White, Joan Osborne, KT Tunstall

[ETA 2020-06-27: added a few more as hints]