I have to say first off that 'Grand Pianola Music' is a favorite piece of mine. I too, am a composer, and open to musical styles of all types. However, where another reviewer hears embarassingly trite, unoriginal and obvious music, I hear music of passion and joyousness, music that might embarass some because it is so unashamed of reveling in the glory of its own sound. Grand Pianola Music is like the big, brassy, colorful uncle who crashes the posh dinner party, horrifies the snob guests and captivates the more open-minded ones. Unfortunately, it seems that despite the talk of reaching out and eschewing the "Who cares if you listen?" mentality of the 20th century academic mainstream, contemporary classical music still retains the atmosphere of a posh upper-class dinner party; having fun is the most gauche faux pas imaginable.
Originality, complexity, structure, and artistic meaning, these are the concerns of too many contemporary composers and aesthetic critics. Beauty, truth, and emotional meaning are the concerns of most ordinary listeners. Which sounds better to you? In the end, it all depends on listening to the music and deciding if you like it or not; if it moves you in your gut. One reviewer found the piano's theme in the last movement of this piece 'obvious' or 'trite' I found it noble and almost Beethovenesque. Make up your own mind.