My instructor has been teaching me improvising since February.
My goal is to pick up any music sheet, and using the chords on the sheet, along with the backing track for the sheet, tob be able to improvise along to it.
On average a music sheet in a major scale can have an infinite number of different chords, which harder to improvise along to.
If you take the 12 bar blues, theres usualy around 3 chords that you can improvise to – so the blues is a very simple and easy place to start improvising along to.
Then you will hear seasoned pro’s say “Don’t get stuck in the Blues”
What they mean is if you want to improvise along to any music sheet, you have to cope with a shed load more chords than the blues (3 chords per sheet on a blues sheet is easy compared to 30 or upwards different chords on a swing sheet)
I’m not knocking the blues, its just a great starting point.
The jazz approach, to start out with, is learn a major scale, play any backing track in that scale and improvise along to it. So you usually end up going up and down the scale, and then all the modes, and then play through various intervals etc.. exciting? hard work! this gets you inside and outside with the scale familiarity.
I haven’t been improvising very long so my knowledge is poor