Stephen, I know your version of Naima is in the key of Bb because you said you have a Bb fakebook. If you had a concert key fakebook, Naima would be in the key of Ab. My advice to always think in terms of concert pitch stands.

But I'm beginning to think the problem here is not that you are two half-steps off, or that your BIAB and sax are not each tuned to A=440. I'm wondering if you are objecting to the choice of chord notes played by the RealTrack artists you selected. You mentioned 'blue notes'. As a test, try using an all-MIDI style. That will faithfully represent the correct notes in all the complex chords. If I'm right and that sounds OK, then your remedy is to purchase a newer BIAB version and turn off Natural Arrangement for the RealTracks.

Another thing you could do is attach the song and let us look at it and try it. Use the File Manager in the Post Options to your lower left.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.