yes i e-mailed "tex" to alert them to look at this discussion here and am sending another e-mail with a link to this thread. I am recalling a battery operated device i ahve for my guitar....it creates a magnetic field which "activates" the string for a sustained sound...reqires a
hand to hold it over the string, but might be mounted somehow...it is an E-Bow--i can envision a set of them one for each string, which could be activated by a foot switch....www.ebow.com/

i recently saw a musician who had an elaborate foot-activated system
so he could record a "loop" played with one instrument (such as a bass
line or rhythm) then play melody along on antoher instrument.