Blues - King (all three) Cray, Hooker, Keb Mo' Taj Mahal but SRV on top
Country - Dwight Yoakam, Gary Allen, Chet Atkins
Rock - Beatles, Stones, Berry, Elvis
Plus others, Stray Cats, Johnny Diesel/Mark Lizotte, Chris Whitley
Realistically it's gotta be anything that's not manufactured completely in a studio and not made solely as an image kind of thing (can anyone say Stock, Aitken, Waterman, Ricky Martin, Britney Spears)
We all know what real music is, whatever style, or you wouldn't be learning/playing the guitar, you'd be off doing your hair and lip-synching to something from the Backdoor Boys.
"I use heavy strings, tune low, play hard and floor it. Floor it. That's technical talk" SRV