I think the problem runs deeper than just using tab. It seems that you have limited yourself to only two options:
- Play a break reading tab, or
- Play a break from memory.
Many players hit a brick wall because they fail to realize the third option, and this is key: improvisation.
Improvisation is essentially writing your own arrangement on the fly. It gives you the ability to play a solo without planning it out prior to the song.
I used to think that the best way of playing songs is to memorize just an awesome solo for every song you know. So I go through Ben’s arrangements, thinking, “Salt Creek, check. Nine Pound Hammer, check. Old Joe Clark, check… I have a great solo for each of these songs!” So when I would jam, I would play the solos I learned here on the site.
Then I’d get the nod for a second solo.
Or a third.
What are we going to do, memorize several solos for every song we can think of? What about songs that we don’t know about yet?
Think of it this way: a song is a jigsaw puzzle, but it’s an odd jigsaw puzzle: some of the pieces are exactly the same, and interchangeable with other puzzles.
So let’s take a look at the Nine Pound Hammer puzzle. We know this one, and the perfect way to come up with the pieces! But we want to solve a new puzzle, the Salt Creek puzzle. Well, if we take the whole Nine Pound Hammer one and try to overlay it, it’s not gonna work. The two songs aren’t exactly the same.
BUT, some of the pieces are exactly the same! We can pull that G to C transition piece and use it. We can use that D to G transition piece. We can use that little tag lick at the end.
Lightbulb!! THAT’S why we learn breaks!
We learn breaks to learn more things to throw in our own breaks!
So I think a good way to start improvising is to start slow. Start out by writing your own break for a song you don’t know yet, and it doesn’t matter how long it takes you. With repeatability comes speed, and you’ll start to recognize common patterns in songs more and more. Writing a solo may take you several hours of stealing licks at first, but if you keep at it, you’ll be able to do it in 10 minutes, and then 5 minutes, and then in 3 or so, and then in the 30 seconds or so that it takes for a verse and chorus of a song to go by. You’ll learn to map out the song’s melody and chord structure.
I’m gonna wear everybody out eventually with my nerdy Rubik’s Cube analogy, but it’s just too good 
I am a speedcuber; I speedsolve the Rubik’s Cube. This is done by recognition of cases and algorithms that are prememorized. Speedcubers don’t memorize the solution every possible scramble of the cube, but they can solve any possible scramble because of common patterns. As we keep doing this, our recognition becomes faster and more natural, like playing chess fast, typing fast, or speaking a foreign language fast. And so much of a cuber’s speed relies on something called “Look ahead”. Look ahead is just like it sounds– looking and thinking ahead to the next step while performing the current step. If what you’re doing in the current step is not ingrained in your muscle memory enough, too much of your mind will be occupied with the current task, which will lead to pauses in your recognition. There needs to be a brief “overlap” in the brain.
Well, it’s the same with music. If we start playing a song and we’re not familiar enough with our options to play over the chord changes, etc., there’ll be an awkward pause in our solo where we get lost and can’t decide what to do.
So practicing improvisation is a lot like learning and memorizing just one solo, but it’s a MUCH bigger picture. We have to keep working at it and exercising it to improve the speed and quality of our improvisation.
I hope that helps somehow. You may also want to read though this thread; I think we discussed this issue a bit there as well: Didn't think I would hit a plateau yet
