I've been thinking for a while now to invest in a really good "pitch/tempo change" software package to help me understand what's being played when I hear Gypsy jazz. The music is never written anywhere...it comes from the mind (complete improvisation).

I'm looking at Song Surgeon but I thought I'd check with you guys for comments before I buy anything. Song Surgeon

No recommendations from musicians I see.
Most use Melodyne however pretty much any decent DAW (Or audio manipulation program) will be able to do what you want.
No harm in trying out the demo to see if it suits, just don't be taken in by there sales pitch as if it is something unique, it isn't.

Bill

Audacity a free software will do that for you.

I LOVE the Yamaha Chord Tracker app. The chord recognition is just “OK” but I use the app to slow down a section of a song, and loop over and over until I play the part. It makes learning by ear so much easier! Also I use it to sing along with songs that are out of my range by using the pitch control. It’s free too!

Also, I’m sure this old news to everyone but I recently learned that you can control the play back speed of YouTube videos. That’s a great feature for musicians learning songs .

A demo artist I know uses Melodyne. He says it is really good. I've never used it but I believe he is sincere.

At the beginning of my guitar career I listened to Johnny Smith. I bought his albums, bought his books, and went to see him whenever possible. I wanted to be him. The voicing of his chords, easy style of playing and his fills were good. His books did very little to help me, they were only notes.

Later in my career I began to play with interesting chord structure, and good fills. I was playing with the taste of Johnny Smith. (Not as good as) There was something new inside me. The art of improvisation comes from within.

Older musicians played what they were feeling. The jazz musician of today has mastered all types of scales, which is good if they are not the main thought of your improvisation.

Mark, listen, listen, listen, you will be doing what you love in a short period. You have good hands and a strong desire, it will come.
John C.

For years I have been using "Amazing Slow Downer" by RoniMusic. Here is a demo:

Amazing Slow Downer Demo

Works great for changing tempo, key, looping. Unless the changes are extreme, you won't notice any warbling. Once you get a song set the way you like it (key, tempo), you can save the song as a .wav file. I have been extremely happy with this software.

For a while, Hal Leonard was featuring Amazing Slow Downer on their play along CDs to allow folks to vary the tempos and keys of their products.

Have fun!

AnytunePro for ios works great