Of course Bob Dylan is probably the king of this topic.
Warning! 90s R&B: This song gave me the idea for this thread. The lead singer sounds like he’s putting on some kind of affectation instead of singing straight.
There was also an 80’s raspy voiced thing from some male singers whose names I can’t think of.
More examples anyone?
Geddy Lee. It was even mentioned by Pavement in the song Stereo.
The Bee Gees’ lead singer. Maurice Gibb?
Beat me to it.
Yep. 
Are you sure you don’t mean Barry Gibb? He was the one noted for his falsetto singing. His late brother Maurice sang lead on average on only one track per album.
It probably is Barry.
Mel Tillis.
Rod Stewart’s speaking voice is deeper than his singing voice.
Prince is a very soft-spoken guy, with very measured, often quite hesitant speech. In song, he’s quite willing to let go, be loud, and be loose.
Here are a couple of live clips that point up the startling difference between spoken voice and (one of her many ) singing voices.
“Soon” (Yes cover)
“When The Rain Come Down” (the startling bit kicks in at about 1:47 and again later on a couple more times)
I know this isn’t what you mean but I am always amazed in Family Guy when you get stuff like Seth MacFarlane as Stewie Griffin doing Bryan Adams because we all know he really sounds like Brian. Surreal.
Bryan Adams was who i was thinking of. Listening to the original, there’s not as much rasp as I remembered. Bryan Adams triggered John Mayer who triggered Dave Matthews.
Also there was an American Idol audition where the guy sang with a heavy rasp to his voice. Simon thought he was putting the judges on and asked him to s ing Mary Had a Little Lamb. Same voice.
Michael Jackson!
I think MJ’s singing and speaking voices are similar except for when he’s doing that gritty thing like in Smooth Criminal.
Was John Mayer around the pop scene before Dave Matthews? I thought it was the other way around, but I don’t really like pop that much.
My contribution: Alison Krauss. I don’t have the capability to access YouTube right now for a cite, but I remember the first time I heard her talk. She was accepting an award, probably around the time she did that song with Shenandoah. If you’ve never heard her sing, you owe it to yourself to check it out, but she’s got one of the most crystal-clear, penetrating soprano singing voices, and it’s really just beautiful to listen to.
When she talks, she sounds like a totally different person.
How about Dennis Day from the Jack Benny show? He had a sort of high, innocent sort of voice - (most likely a character, but it seemed to stick) - on radio, but when he sang, he had an amazing tenor voice.
How about Axl Rose? Here is an example of him talking. We all know what he sounds like when he sings, of course.
