RealTracks and RealDrums are actual studio-recorded performances by real musicians, using real instruments. They are essentially audio samples of what was played by the artist. BiaB can use these pre-recorded sounds to form a complete song, including tracking the user's own chords, tempos and even key changes.

As an example, if you don't wish to use the RealTracks Sax sounds that are available, you can only create your own Sax sound using MIDI and a Sound Module. It's unlikely you'll get the same results, as all of the nuances of the live musician's performance are difficult to replicate with MIDI.

BIAB & RB2025 Win.(Audiophile), Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors, AKG K271 Studio H'phones