Prince was at least in the class of the greatest guitar players of all time, he just didn't cut loose all that often like many who focus on it as a primary function. he was also a heckuva prolific songwriter- not only for himself. gotta give him credit for his contributions though i'm not the sort to sit and listen to him for extended periods.
Tom Petty is authentic... that's the better word imHo...
a good example is Chris Stapleton's new album lead song "millionaire"... it's a good song, and I appreciate his rendition... but the original artist (and writer) Kevin Welch (and who is a friend of mine) is 'authentic'... it's evident in the delivery, but i can't put my finger on exactly why. All of Kevin's music is authentic, except for one which was sold to Garth Brooks (who changed some of the words and took shared ownership of writing because of) "pushing up daisies"- Garth's version, who'm he dedicated to his father, is presented with a lot more attachment than Kevin's, and seems more authentic...
same argument for 'Hurt', between Cash's or Reznor's, Cash stole the show... I've heard it said Reznor was born to write that song, and Johnny was born to sing it... all of the studio theatrics of Reznor's original version detracts from the song, where Johnny's vibrato and aged chords rattle it out to where you flat out believe it.
authenticity is where it's at.... somebody posted SRV- and THAT dude, when caught jammin', was absolutely authentic- 'life by the drop' and (Hendix's) 'little wing', both in acoustic, i could listen to back to back for days on end... even SRV playing little wing electric through that old tubed amp has some sort of transcendent quality to it that pulls you right into it and in a way reserved mostly for classical music.