I need advice about jazz improvisation

Yo, I'm stuck at some sort of musical block in my jazz playing, namely improvising. I just about a year ago got out of my blues/rock phase to explore more challenging material. My sight reading is fine, and my understanding of the theory is superb, but my improvising is trash. I'm stuck using the major and minor pentatonic, and although I know which scales or modes would fit any particular progression, anything I play besides the pentatonic sounds linear and predictable. I think some of what I'm looking for is to be able to nail the chord changes, but what does it mean exactly to nail a chord change? In terms of arpeggios, I'm hardly able to throw out the correct arpeggios as fast as the chords change. However when I do pull this off, its sounds very predictable because I've never figured out how to link the arpeggios together for a smooth transition.
I have lots of time on my hands and I practice at monstrous amounts everyday but I don't think I'm using my practice time to its full potential because I don't know really what I should be focusing on to improve my Jazz improvisation. If you have any tips or recommendations on how to improve my improvisation, if you could push me in the right direction it would be awsome.

Yeah, arpeggios are where it's at, especially when learning this stuff. You seem to know your answer, but just haven't applied it yet. And you'll take forever to get there if you're trying to learn "at full speed" during a song. :) To learn this stuff you really need to stop and think about it, rather than just hope it all comes together on the fly. Once you know what you want to do you can practice it during songs.

You might wanna take something simple first, without too many changes. Take the first chord and learn its arpeggio in at least two or three positions. Figure out a few little licks to experiment with. Now play your backing track and, ignoring all the other chords in the progression, play around with your arpeggio runs for this first chord. Rinse and repeat. Then do the next chord on its own. Then do them both. You get the idea, eh?

Do all this with modes as well, even with the modes that don't make any theoretical sense played against your chords. Everything can be useful in a certain context.

Something else you'll want to look into is substituting chords (and thus scales and arpeggios). But you say your theory knowledge is superb, so I won't bother you with details about this. ;)

All great advice. Another thing to remember is, don't be afraid to break the rules for the sake of being interesting. As you surely know, jazz is primarily about spontaneity, and in this way theoretical structures are a two-edged sword: they can give direction to your improvisatory playing, but they can also box it in. I'm not saying you should forget all your scales and modes and just mash up the fretboard (like I do :o), but if you find yourself sounding predictable, try putting the rules out of your mind, if only for one or two phrases, just to restore interest. Throw in some unusual intervals and double stops, inverted arpeggios or accidentals, not minding for a moment whether they are theory-kosher. If you do this kind of thing strategically, you can bring a whole new level of expression into your improvising that will contrast with the more melodic side of your style. Don't let it replace it completely, though, unless you want to sound like Derek Bailey! :eek: :D

Hope all that rubbish was able to help some. Sorry if I was just telling you things that you already know.

Thats right, stick to arpeggios, scales minors and majors, Learn and study Jazz chords Major and Minor (7,6,9 11,13ths augmented, diminished,etc) and different voicings for chords used in Jazz Method Books. Try to apply different arpeggios or scales for each chord voicing in a song for soloing or improv.
"Think outside of the box" (pentatonic) and when you get lost go back to the box.
Learn different rythms, like the swing feel for be-bop
Bossanova and latin have a different feel rythyms as well.
Have patience and yes theory is a +. Good luck in conquering the Monster of Jazz.
There are several books on Guitar methods you can check out.
Mel Bay's complete Jazz guitar Method will give a structured idea.

Wow this thread really helped me, despite being short on actual theory.

In any case, yeah, arps are where its at. To tell the truth, the chord changes in a lot of jazz songs are simply too fast to "nail" so to speak. I honesty dont even bother trying to keep up with chord changes. Also please try and get out of the pentatonics thing. I find its so bad for people to first learn teh pentatonics rather than the full minor and major scale. You just run into problems later cuz youa re so used to having a basic sound from the pents to the extent that when you do play the full major or minor scale, it will just sound wierd to you.

Also something you can do is to take time to listen to the backing track/ song or whtever. A lot of jazz uses the 2-5-1 progression, no mater how complex them may sound. What causes (IMO) a lot of the complexities in jazz is that notes and chords that are not diatonic to the major or minor scale are thrwon in. Despite all this, there is still an underlying harmony which you can try and listen out for.

Experiment with dufferent modes. If you do have a 2-5-1, dont just use the major scale, you can use the dorian which is the scale starting on the 2nd degree. Since you know your theory i wont even bother going into all that. Yo can even mess around with chromatic runs when you know there is a chord change coming soon.

Jazz is fun and challenging :).

dont let the chord guide u guide thru the chord find the intervals that go well with the chords and use them for expression. if u have an idea dont stop going up the neck keep going. most guitarists will stop and find there comfort zone u gotta keep going up if u have an idea just keep going doesnt matter what key as long as the intervals fit with the chords. say if u have a pentatonic lick with some hammers and pull ofs u do that in the obvious key lets say the fist chord was g do the petnatonic lick in g then find the intervals that fit with the chords and keep going with the same lick. in every interval
i hope that makes sense. now for using modes ur job as a guitarist is to make the listener exposed to new ideas with the melody. so basically when ur in a band u want to take them on a journey. decide which note u wanna start with and end with and flow inbetween.
hope it all makes sense.