What was his most famous pieces.

http://www.google.com/url?sa=t&rct=j&q=arnold%20schoenberg%20pieces&source=video&cd=1&ved=0CDIQtwIwAA&url=http%3A%2F%2Fwww.y
outube.com%2Fwatch%3Fv%3DN2ZMnLENKVs&ei=_ylZU5LCMdGwyATe-oII&usg=AFQjCNF2LFMZkqt9BTwAim-_KW3gC6ULew

Five pieces for Orchestra

It was called

http://en.wikipedia.org/wiki/Five_Pieces_for_Orchestra