313-314. Are these Godunov to post?

M.M. was a 19th century Russian composer.  He also wrote an opera, Boris Godunov.
Of Modest Mussorgsky I'll tell.
Pictures at Exhibition is swell!
For piano he wrote,
Then Maurice took each note
And transcribed it for orch., Yeaaa Ravel!

Modest also wrote Night on Bald Mountain,
A work that erupts like a fountain.
Wrote a few other things
Mostly kept in the wings.
How many?  They're hardly worth countin'.