Jerry Garcia was doing a folkish type thing for awhile. I saw a documentary on it. I liked it. Can’t remember the guys name who was with him. They had a cute play-on-words name for their deal.
Joel mentioned in an interview that he never set out to be a performer. He wanted to be a songwriter and have other people perform his songs. However, he was advised by people in the music business that if you want people to hear your songs you need to make an album and then go out on tour in support of your album. That’s how his first album Cold Spring Harbor came about. The problem with the album was that it was recorded at the wrong speed and wasn’t promoted properly. When it was remastered years later, Joel said he still didn’t like it, he thought he still sounded like a chipmunk. Perhaps if Joel had his way in the beginning, he’d be known as a Broadway writer today. His music was the subject of the Broadway musical Movin’ Out, which was a huge smash.
Gram Parsons.
His first name was Ingram, shortened to Gram.
Mick Mars considers himself more of a blues musician, I’m not sure how he ended up in Motley Crue.
They would be lucky. Most artists wouldn’t have a place to go. The Eagles actually prophecied the sound of country radio.
Barbara Mandrel started out hard core country. She played pedal steel guitar and was very, very good. Also played banjo and guitar.
Later in life she did cross over into country pop and R&B. Her tv show featured a lot of pop tunes.
If the category was just “Heavy Metal”, everyone would have a point - but it was “Hard Rock/Heavy Metal” and I’m sorry, the Tull can rock as hard as anyone. All the criticisms of the award that take pains to call them “folk rockers” are just showing their own cluelessness about the breadth of Tull’s œuvre, never mind Crest.
And I’m less inclined to sympathy because of all the people who think it’s Metallica that was robbed, and not Jane’s Addiction. I mean, I love “One”, too, but seriously…
I’m pretty sure that the overwhelming majority of flamenco or classical guitarists don’t use picks or electric guitars.
I don’t know much about Clark. Based on that video, he looks like a top player ideed, but the music itself sounds like a stereotypical imitation of the genre.
Dawg Music with mandolinist David Grisman.
Interesting thread. I’m one of the Billy Joel on Broadway guys, so +1 me there. Springsteen in his way, too. Epic stories of hope loss and redemption. Or a novelist. Steinbeck in leather as they say.
Beyond that, I’ll think about it. From a guitar standpoint, hearing Jeff Beck play straight up rockabilly or John 5, guitarist for Marilyn Manson and Rob Zombie, kill on bluegrass and country chick’n pickin - or Roy Clark nail the Malagueña - there’s a lot of that. Most swim in one lane, but grew up woodshedding all kinds of music.
The Eagles were originally played on all the top 40 rock radio stations. It was like that all through my high school and college days.
I still do a double take when a country station plays the Eagles. But, they fit with what people call Country music these days.
Many people don’t know Conway Twitty started as a rock star, following in Elvis’ footsteps. Recorded with Sam Phillips and Had several hits in the early 60’s. He always insisted he should be in country. Things finally blew up and he walked off stage.
Great story. He ended up a huge country star with over 40 number one hits.
Speaking of the Stones, they sound better as an actual low-down blues bar band, not an over-produced (for the genre) version of the same. Ironically the only album song of theirs I like is Sympathy for the Devil which is pretty far from bar blues.
Or, Old and In The Way.
Tom Waits. Put him in a genre, and I’ll explain why he doesn’t belong there.
Interesting topic. First thing that came to my mind was Jack White, although I’m not 100% certain he’s in the wrong genre as OP requested, but more along the lines of he could excel at a few other genres as well…
If I saw Jack White in a sleazy dive bar in New Orleans, beating the hell out of a slide guitar in a blues band, it would be perfect.
If I saw Jack White in a small music theater in Nashville, playing Rock-A-Billy guitar with an unknown country singer, it would be perfect.
If I saw Jack White in an arena, with a huge rock band, playing giant riffs and covering AC/DC songs, it would be perfect.
An aside, back in the 70s as a wee tyke, I saw Roy Clark and Buck Owens together at a county fair. It was the greatest moment of my life to that point 
I still remember them doing a ‘dueling guitars’ version of dueling banjos that knocked my socks off.
Garth Hudson ( The Band) should have been a church organist.
I think he was a musical genius but not much of a rock star.
Songwriting?
But he’s a very successful music teacher. 
I think Jack White and Jack Black would together make an excellent classic rock band.