Similar sounding bands.

Talk Talk -- Roxy Music!

All blue grass bands by default.

Beatles-Oasis very obviously;

Alman Brothers -- Greateful Dead -- Steppenwolf -- Doobie Brothers -- ARS -- Kansas -- Don McClean -- Harry Chapin -- Bob Seger and most of the most of the southern rock;

Boston -- John Bon Jovi

Hey, anyone called their gig Chalkboard?
Here's more to laugh:
Kenny G -- Celine Dion
Aretha Franklin -- Teddy Pendergrass
Hall and Oates -- Linda Ronstadt
Nina Hagen -- Yma Sumac
Yanni -- Carmen Cavallaro
Nina Simone -- MLK

I like all styles including country. I also realize the skill you need to have to perform bluegrass! I can spend a time to listen to one or couple of bluegrass songs and tunes and even enjoy that, but after being at bluegrass festival, I realized all songs and bands sound same and bass can be done via computer for all bluegrass songs. Same notes, same rhythm, same harmonies, same instruments and very very often SAME WORDS too. It doesn't need to be into or not into it just same all over.  

Blue-grass song structure:

Variation A(for woman):
He's bad, he left (her) for another woman and she's alone and blue and crying

Variation B(for men)
She's bad, she left (him) for another man and he's alone and blue

Beatles->Loving Spoonful -> Jefferson Starship/Airplane -> Badfinger -> Monkees