Just if you're curious, Ravel also wrote some wonderful music for piano four hands. I am familar with three works (that may be all of it):Ma Mere L'OyleFrontispiceSites Auriculaires In general, his four hands music is not quite as challenging as the solo music. But they of course still are at least of intermediate level. As far as his chamber works go, the piano part in his Habanera is not too challenging, however the parts in his Trio, and the two violin sonatas are quite challenging. I'm afraid I can't comment on his songs though.