I believe that the japanese version of Kraftwerks Pocket Calculator was called
'Dentaku'.
The only pre-techno Ongaku that I've heard of is the song by YMO that someone
mentioned. I believe the original version ('After service' is a live album) can
be found on the 'Naughty Boys' album. Unfortunately not a very interesting
song though (in my opinion, but then again I don't speak japanese...)
Fredrik / RND