Re: Michael Jackson: I think he picked up those hiccups and hoots after the song I Just Can’t Stop Loving You (done with Siedah Garrett). In the book “The Billboard Book of Number One Hits”, she says:
"When we were doing it, I didn't realize how much we were sounding alike. Michael is a vocal chameleon; he can sound like anyone."
Re: Jeff Lynne: Listen to the Traveling Wilburys, and I have a hard time figuring out Jeff Lynne or George Harrison.
But for your consideration:
Rick Astley
Patsy Cline
John Denver
Carole King
Linda Ronstadt
Jim Nabors
Johnny Mathis
Nat King Cole
Bing Crosby
Caruso
Mario Lanza