Similar sounding bands.

Robin Trower did Hendrix
Starcastle did Yes
Tom Petty did the Byrds, Dylan and everything in between

Czarivey  said  "All blue grass bands by default"

Time to turn in your music card. :)

Music lovers - lookup Sierra Hull and Balsam Range and spend a night with acoustic music.  
You will need a quality system to appreciate the mastery of these musicians. 

Any genre can sound "all the same" to a listener not into that genre, including Bluegrass. It takes some listening experience to develop the discernment necessary to discriminate between the practitioners of some music. If one doesn't like a particular genre, he or she won't invest the time necessary to do so. LOTS of people don't like Bluegrass, or even Country.

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.  

Susan Tedeschi and Bonnie Raitt have similar sounding vocals and vocal styles, IMO.