Should guitarists listen to horn players?
I recently read a Jazz Times interview with Russell Malone and George Benson. During the interview, Malone made some disapproving remarks about guitar players who say they only listen to horn players. He said some words to the effect that the guitar was meant to be "caressed", not blown into, and that guitarists who model themselves on horn players aren't "using the whole instrument" or something like that.
In one way, I see his point. No matter how you try to cop Coltrane's phrasing or study Clifford Brown's solo on "Cherokee", at day's end, you're playing a GUITAR. There are certain things guitars do well; there are other things they can't do at all. You have to work within the parameters of your instrument, right?
Well, you can accept the guitar's limitations grudgingly! If players had all accepted the instrument as it was without trying to expand its horizons, we'd all still be sounding like Eddie Lang! (Which is no slam on Eddie, but, for most of us, times have changed.) There'd be no Charlie Christian to make records for Wes Montgomery to study, therefore no Wes for George Benson to study and no George Benson for Russell Malone to study.
Personally, I embrace the "electric" in electric guitar. (The electric part is what lets me "caress" it when I want to - and still be heard!) The instrument can be made to sound a lot of different ways, and I will make it sound however I need it to sound to help me say what I want to say. If my music calls for a "warm hollowbody sound", then that's what it'll get. If a heavily distorted envelope-filtered Strat with digital delay and ring modulator is needed, then I'll do that. If I need to pick every note, OK. If I need to slur a bunch of 'em, sure. If a phrase might sound good with right-hand tapping, I'll try it. Musical expression should dictate choices in technique and equipment, not the reverse.
As for listening to horn players, how many guitar players in jazz have contributed to the music in the ways that Louis Armstrong, Lester Young, Charlie Parker, Miles Davis, etc. have? You could count them on one hand (and, in my opinion, you'd have fingers left over). The purpose of listening to non-guitarists should be not to literally copy them but to absorb the ideas they bring to the music. As a guitarist, you can't sound like Sonny Rollins - but you can figure out why his solos are so great, and maybe identify some concepts in his work that you could employ in your own.
How about piano players? Earl Hines, Art Tatum, Bud Powell, Wynton Kelly, McCoy Tyner, Bill Evans - there's a very short list that would provide a lifetime's food for thought.
By all means, check out the guitarists too. Django, Charlie, Wes, et al. have all made distinctive contributions to the art of jazz guitar. We should all know their work. But we shouldn't stop there!
Another thought: how about guitarists who aren't known as jazz players? Because I'm a jazz player, do I have to shut myself off from everything else? (Or can I be like Miles, who checked out Hendrix and James Brown as well as Stravinsky?) I hear some rock guitarists (Eric Johnson, Jennifer Batten and Steve Vai, to name a few) doing very fluid and difficult things on the instrument. Their musical content doesn't always appeal to me, but what if I used their technical methods to play ideas I like better? (I'm still working on that one; I'll let you know what I find out.)
Concerning the "using the whole instrument" statement: unlike horns, guitars are capable of chordal or polyphonic playing, but they can also be played monophonically like horns. Some people get caught up in one approach or the other. Most explore both to some extent. For example, Scofield is not a renowned 'chord melody' player in the typical sense, but he frequently plays harmonized passages in his group arrangements. His solos are filled with incredibly creative lines, and he has an unmistakable, engaging instrumental voice. Who cares that he can't play a rousing solo rendition of some obscure show tune? Life is not long enough to totally explore all the guitar's possibilities. With that in mind, I think it's best to first explore the possibilities that appeal to you the most. Those will probably lead you to others eventually.
Music generally starts with a sound the player hears in his/her head. If you want to be a George Benson soundalike, fine. (Start practicing now!) If you don't, that's fine too. (Start practicing now!) Only you know what the sound in your head is. Listen for it, don't give up till you hear it, don't let anybody discourage you from searching for it - and don't discourage anyone else from searching for theirs!