You're talking about a mainstream band doing a complete musical 180 which would be commercially unrealistic. You could slip a couple tunes of a different niche in your album, or do a solo album and such. If buddy from Metallica went and did a ... I was going to say a jazz combo album (then argue he can't and blah blah). I talked of versatility but what does it matter. If you're good at rock then odds are you can diversify into all rock associated music styles, which is personal opinion - not personal limitations. Jazz and classical are specified art forms which no doubt requires a musicians full attention no matter what level his or her theory/technicality is at. SRV had no theory but I'll bet if he had started off on jazz and spent the time on it as he did on blues, he'd have been just as competent at it as blues. It's all relative and of no consequence. They're all good guitarists whether they've got theory or not. Does precision sell more than emotion? Take your favorite of both and which is more commercially successful? That doesn't quite work either. I can't remember what I'm arguing anymore.