Firstly, here's the good form. The great and almost criminally under-appreciated Chuck Thompson playing with Hampton Hawes, and Red Mitchell. The tune is "Blues the Most". YEAH!
Now here's the bad form. (Caution: Rant Alert!)
If you want to let me know about your gig be it by email or Social media, PLEASE ONLY TELL ME ONCE! I've been getting a lot of "Spammy Davis Jrs." lately and it just gets me feeling you're inconsiderate and that probably extends to your music as well.
Now, keeping the form.
I'm not sure if I have related this story, but nevertheless it bears repeating. David Liebman did a workshop while I was attending St. F.X. University in the early '80s. It was the first time I had been exposed to a working Jazz musician of that caliber and it was very exciting, as well as terrifying!
Liebs played a jam with the students one night and Mike Downes and I played a tune with him. I've forgotten what selection, but Mike tells me it was "Confirmation". Mike has since said as we were playing he started thinking "Uh-oh, I think we've played a lot of A sections in a row". I'm afraid I wasn't even that aware at that point. After we finished, Liebman said in that awesome accent of his, "C'mon guys, the form, THE FORM!" Both Mike and I felt pretty bad about this, but it meant that we both worked very hard on this particular issue and rarely have had a problem with it since.
Was that a bit embarrassing to have Dave Liebman taking us to task on messing up the form? Yes. Was he right to tell us about it? Absolutely! This has come up recently because sometimes I find myself in situations where the form is getting messed up and even the people who are correct bail immediately and change where they are to suit the culprit who is off the rails. Don't do this unless there is no hope of the soloist finding their way back, especially if it's a casual gig or a jam session. Nobody learns anything unless they're aware of when their messing up.
On the other hand, in an improvised music, stuff can happen....
Case in point, check this out. The tune Joshua, is a bit weird, form-wise. To begin with, the head and solo forms are different. The solo form is 12 bar A (although it's not a blues), another A of the same length, then a B section that's 6 bars of 3/4 and 2 two of 4/4, repeated 3 times, finally there's one last A section. Herbie misses an A section in choruses 2 and 3 of George Coleman's Tenor solo. It's still a great performance and Herbie is still one of the best living improvisors around (and a personal favorite).
Jazz, especially back in the day, was recorded "without a net" and the process was more important than the product.
A couple of more tips about keeping form.
1. Learn the melody
Many tunes have similar chord changes, but the melody is unique. Know your melodies, and you can always find your way back if anything goes awry.
2. Think of the form as one unit.
As soon as you learn the melody, try to see the form as one 32 bar, AABA, or blues etc. chunk that's being played over and over again. As soon as one gets into say, thinking of So What as Dmin for 16, then E-flat minor for 8, then back to Dmin, for 8, you're asking for trouble. Which Dmin. section are you on? The form is one thing, not a bunch of little harmonic pieces.
3. Keep your place in the form when you're listening to music. as well.
This is a great way of working on forms. Eventually you will be able to keep your place even when you're not listening that carefully, and you'll not instinctively when the form is wrong.