Glad to see that everyone is still talking this out. Let's not slam any doors.
Having spent some time reading about this topic, I now realize that I was probably going too “macro” in my approach. What I SHOULD have been doing is to isolate one little PIECE of language and mining THAT from top to bottom.
So my recent approach—and I’m early into this—is to do the following:
1. Identify a vocab chunk I like
2. Drill the crap out of it by itself (trying to maintain good sound, phrasing, etc.)
3. Start the idea on different beats of the bar and drill those a bunch
4. Put on tunes and play the original idea and permutations ad nauseam so I can hear how they lay over the music
5. Re-orchestrate the idea and drill that a bunch with and without music
6. Come up with rhythmic variations on the idea and drill those a bunch with and without music
(I'd also add that if the chunk appears in triplets, try it also as 8ths, 16ths, sextuplets, and 32nds, in order to build facility and familiarity, and possibly discover a new thing.)
What's missing from this approach (and you may instinctively be doing this already) is the "why" and "how" -- that chunk of vocabulary might have been developed not as a deliberate "lick", but as a rhythm with a sticking applied to it, or a combination that is being displaced or syncopated, or a rudiment with a limb substituted, etc. For example, what you might initially perceive as "vocabulary" or a "lick" may actually be derived from filling in the space between Syncopation exercises, and quite possibly be executed on the fly.
The specific thing I’m struggling with—and I don’t think I’ve been able to articulate this properly in this thread—is the idea of taking a little chunk of vocab from, say, Philly Joe, and getting it IN to my playing.
No one can say exactly what will work for you 100% of the time, but this phrase:
getting it IN to my playing
leads me to think that you should play time for a measure or two or four, and then transition into the "chunk" (without stopping, and maintaining steady tempo), and then transition back. Are you practicing specifically in this way? If you play the chunk by itself, but then stop before you play something else, it's bound to feel awkward when beginning or exiting that chunk.
Assuming you can play the chunk in time and along with some other pattern or time-keeping, it's time to practice with play along material that allows you to trade 4s. This is as realistic as it will get, outside of rehearsal or a gig. The rest is nerves.
I think some here would outright discourage you from doing learning a phrase or chunk and "reciting" it on the gig -- because, of course,
it's not improvisational -- but I don't see a problem with it, in small amounts. It's a place to start, and is certain to build confidence, which is hugely important to improvising well. If you end up quoting verbatim some Philly Joe solo vocabulary on a gig, and you do so appropriately, what's the harm? The jazz police are not going to arrest you! Sure, it may not be the most original thing ever played, but you get the opportunity to try out that vocab, and you'll probably end up changing it into something else, over time.