Walker's first major orchestral work was the Address for Orchestra. His Lyric for Strings is his most performed orchestral work. He has composed many works including 5 sonatas for piano, a mass, cantata, many songs, choral works, organ pieces, sonatas for cello and piano, violin and piano and viola and piano, a brass quintet and a woodwind quintet. He has published over 90 works. He has received commissions from the New York Philharmonic, Boston Symphony, Cleveland Orchestra, Philadelphia Orchestra, and many other ensembles. He is the recipient of six honorary doctoral degrees.
Walker is the father of two sons, violinist and composer Gregory Walker, and playwright Ian Walker. He resides in Montclair, NJ.