For those who haven’t seen this (and I hadn’t) – Mariano Gonzalez demonstrates that you can play the equivalent of a double strung harp, using 2 harps-
Michael, another harpist, Betsy Mills, had a long restaurant job in California, about thirty years ago, playing two instruments at once: an electric keyboard with one hand, (I seem to remember her left), and her pedal harp with the other. It was very pleasing to hear, especially as she could sustain bass clef
Patricia, Since you mentioned it, I decided to play around with my little sampling electric keyboard from 20+ years ago, and my harp – I see that it could be done, in various ways- the main part of the trick is positioning the keyboard so that it is conveniently located.