So I have a tune composed in BIAB using all Real Tracks (no melody yet--just the chords and the form).

I want to record a melody I wrote for the chord progression/form using my Casio CTK-6000 arranger keyboard, but I want it to record audio, not MIDI, and assign the melody to a Real Track instrument. How do I do this?

Alternatively, I can easily record a MIDI melody to the tune, but is it possible to convert the MIDI melody to a Real Track instrument so that I have all audio?

(BIAB 2021, Windows 10)