Does anyone know of a good free program I can use that will play through chord progressions that I can practice soloing over? Kinda like Band-in-a-box if anyone knows what that is, but free. yeah, I've got a jazz performance coming up and I really need some way to work through the key changes
that's a pretty sweet site... but i was looking more for something where i could put in the specific chords that i could solo over. or maybe something with the backing tracks of some jazz standards
Maybe you can buy some Aebersold books: They come with the changes and a cd to play it over.
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hey man, you don't have to have a program for this. Just set up a song list and play leads throughout the song. This will teach you how to play along with a singer which is something you have to learn to do if you want to play in a band. Also you can throw yourself curve-balls with songs you've never tried to play and try to find the key they are in. Imo this is a huge part of learning the music. Once you can hear a song and know the key then a lot of the work is done for you. The rest being able to play what you want the crowd to hear.

PS. It's also beneficial to be able to play along with a lead. It may not be original but it's part of the learning process. Taking influences and putting your own blend into your licks is a crucial part of learning.
Before the day's of internet, computers and Abersolds, people would practice going through the changes by playing along to a record and ignoring the soloist. this also has the benefit that you can pick up a few ideas from hearing what that player is doing.