Hi Folks,  Although, strictly speaking this is off topic, some of you
might enjoy this reasonably palatable short summary of the history
of electronic music with demonstrations of electric/electronic tone
generation.  It is at the IEEE (Institute of Electrical and Electronics
Engineers) Virtual Museum:

http://www.ieee-virtual-museum.org/exhibit/exhibit.php?taid=&id=159271&lid=1&seq=1 

Jim Heyworth,
Sechelt, B.C., Canada