With all of these continuous input channels available, the Sackbut came alive in the hands of a trained performer, as can still be heard in LeCaine's recordings, such as the excerpt presented here (1.3 MEG3 Audio) (recorded in 1952), where we hear him emulate string sounds, play a string quartet (familiar excerpt from Gluck's Dance of the Blessed Spirits), and do a very early synthesized blues number. See this site for more information and this site for a good photo.