RunandWrite,
I think you are asking one question and our fellow forumites are interpreting it as another.
I think what everyone other than Tony thinks you are saying is “Hey, I recorded a bunch of YouTube videos of me playing my saxophone over a backing track I made with BIAB. Are there copyright issues with that?”
I think what you are actually saying is this: “I made a bunch of backing tracks that I generally use to back myself up when I play the sax. I think it would be cool to share these backing tracks on YouTube for other people to use.”
If I’m correct about what your inquiry actually is, then the answer is, if you are careful about how you do it, you can avoid infringing anyone’s copyright.
First, you can freely distribute recordings that you have created with BIAB, as long as you’ve not infringed on the copyright of a third party.
The next thing to consider is this: The chord progression of a song is not subject to copyright, so as long as you haven’t recorded the melody of a song or some readily identifiable riff, you have not infringed on a copyright by providing a backing track of chords created by BIAB. Tony has already made this comment.
But you are not home free just yet. It’s been my observation, that you can run afoul of someone’s copyright ownership by identifying your background track using the copyrighted title of someone else’s work. For instance if I use BIAB to create a backing track for the Beatles song, Yesterday, and say that here is a backing track for Yesterday, I probably have infringed on Lennon and McCartney’s copyright.
However, if I say something like, “Here is a song about the Day before Today by The Liverpool Four, I’ve probably done enough to communicate what the backing track can be used for without stepping on John & Paul’s rights.