Whether you are a professional musician or a beginner one of the best ways to practice improvisation is to use play along's or backing tracks.
Throughout my career I have composed hundreds of tunes to which I've created original backing tracks that are an excellent tool for learning and to perform live. 
The music I have is technically challenging offering the musician an opportunity to develop his/her technique. At the same time the harmonic structure of the tunes is rich and original and learning them will open many doors for the improviser. All of the sheet music can be purchased in concert C, B-flat or E-flat. 
This is a fresh and new approach to jazz improvisation. With modern rhythms and Harmony. With strong influences on world music and fusing elements from cultures from around the world.
Pick any tunes you like from any of the Electronic Jazz Projects.
Write to me and let me know what tunes you would like! 
The cost is $2 per tune.