Japanese singers of the time?
Here's Li Xianglan (chinese name, but japanese singer), in Yelaixiang, sung in a mixture of Japanese and Chinese
https://www.youtube.com/watch?v=Dt7QJ9_nY38
in a chinese song
http://www.youtube.com/watch?v=BncpL0wGFlY
and there's even a song for italian JFB (Greyjoy, if you're reading this)
http://www.youtube.com/watch?v=G0snbqMdEhI
For a later one, but with a great voice, try this :
http://www.youtube.com/watch?v=FpXJ932AHXg
and this
http://www.youtube.com/watch?v=e7LcnE_M67Q
And, even less related, when attacking Yenan, and if you know a bit about Carmen, you can watch this, featuring an outfit which might be the Eighth route army, and some Americans troops, too...
http://www.youtube.com/watch?v=wQJMTeCkiyc
[ETA] Oh, and I forgot... even less related, but still japanese and which might suit a gorn-mind
http://www.youtube.com/watch?v=8xK8c4YtOqU
http://www.youtube.com/watch?v=Y-tRDirpvwQ
Francois