...appears to like Frank Zappa?

Sorry, that is incorrect!

Hint

Mick Ralphs appears to be in _ _ _ / _ _ _ _ _ _ _

the bathtub?

Ok, the answer:

Mick Ralphs appears to be in Bad Company.

Mick had just left Mott the Hoople to form the group Bad Company.

In the Little Feat song, who is in the bathtub?

This is the Central Scrutinizer. As you can see, music can get you pretty fvcked up. Take a tip from Joe: do like he did, hock your imaginary guitar and get a good job. Joe did, and he's a happy guy now, on the day shift at the Utility Muffin Research Kitchen, arrogantly twisting the sterile canvas snoot of a fully-charged icing and anointment utensil. And every time a nice little muffin comes by on the belt, he puts forth...

...a little green rosetta, a little green rosetta, it makes a muffin betta

...a little green rositti, a little green rositti, it's really really neat-y

SOME PEOPLE LIKE CUPCAKES BETTER.
I FOR ONE CARE LESS FOR THEM.

Dang you guys know lots of esoteria.

Little Feat...dog in the bathtub? (not even a clue)

Where have you been all my life ???

There is a fat man in the bathtub, with the _____.

Finally one I know!

What does said fat man have?

Standin' on the porch of the Lido hotel
(Floozies in the lobby love the way I sell...)

Bubble bath?

Nope but that might help.