Help with musical form.

[countrymath]

Im learning popular improvisation (country, rock, ballads, etc.). I know how to play the styles, i have some harmony knowledge (i studied the Mark Harrison Theory Book), but I dont know how to create the "form" of the music.

I mean, how to create the AABA sections, how to create a bridge, a chorus, etc...

Can anyone help me?

[prometheus]

It can be as simple as you can imagine. If you have two pieces of music that are not identical you can call one A and the other B. You can then create any structure made up of A's and B's.

A bridge is literally that. It connects the previous and following sections of the piece. What the purpose of a bridge is may differ. But in pop music it is generally contrasting with the chorus and verse and the only piece of the song that is never repeated.

Improvisation generally has little form. Form is something which is a specialty of classical music.

Jazz musicians just take a preset bunch of chords and improvise over these chords, which they repeat as long as they want to play.
They take a song that was written with a certain form. They play the main melody of the song first and then they just have several bars of chords taken from the song which they improvise over. Basically such a improvisation has no form. If it had more form, it would be impossible to improvise over. And if it wouldn't be impossible, it wouldn't make any sense anyway.

Just as you can't improvise a sonata form, you can't have form in an improvisation. It's too complex for the human brain.