I was doing some work while hanging out with a friend. Then a song came on and I asked, is that the Grateful Dead? She looked and low and behold, it was. She asked how I knew especially since I've never heard that song before and I told her that some people musically establish identity on their instrument.
Most people can know BB King's signature vibrato, KWS, SRV, Grateful Dead, Morello, Slash, Hendrix, Van Halen, Gilmour... the list goes on but not that long.

My question then is identity formed from style? Or is it many more elements? Is it sound? Is it licks they made their own? What's everyone's take on this?