This is a first for me. Have been playing around with Midi for years since it cam out.  I now think I have found real way to use it for me.  Using my Technics KN7000 as the base keyboard.   I went Midi Out to Yamaha PSR S770 Midi In.  Split both keyboards to the same “F# 2” key.  Using Fingered Chords for both and compatible rhythm patterns I tried ‘playing a song.  The song is “Satin Doll” by Duke Ellington.  Using both backgrounds together with fills and pattern changes I was amazed of how the blended to together so well.  Taking a listen and judge for yourself?  Hope you enjoy!