Fans kept hoping that his next piece would be another shocker and they were sorely disappointed. Ornstein withdrew from concert life, took up teaching in Philadelphia and for all intents and purposes, vanished.
The outer events of his life can hardly be considered dramatic. He retired in the early 1950s and has lived quietly ever since. Yet still he composed.
His compositional method deserves comment: Ornstein hears the piece complete in his mind and then plays it. Writing it down might happen years later. Usually he did not forget, but some early sonatas vanished over time. For many years his devoted wife, Pauline, notated his works as he played them for her. In fact, it was she who often 'forced' Leo to the task at all. When she passed away in the 1980s Leo Ornstein had to take up his pen again.
Around 1990 he produced his 8th Piano Sonata -- a massive composition of great virtuosity, combining vehement ideas with others of the simplest naivete. It is, quite simply, a great work. Even ignoring its production by a man of his age (whatever it might be) it is amazing. How many other composers have had such long lives of creativity? Over the years he wrote many works for piano, a wonderful piano quintet, chamber music, songs and orchestral works.
Some of Ornstein's music has the barbaric rhythms, of say, Stravinsky. But other compositions sound tonal, more fluid -- almost like a Keith Jarrett improvisation -- not jazz, but something else where tonality shifts freely, where melodies have strange but recognisable shapes (and Ornstein has a clear signature in his melodic writing with a bit of the Hebraic thrown in).
Interest in Leo Ornstein has gradually built up with articles and dissertations appearing over the last thirty years. A few recordings have been made, though they have not grabbed attention as they should. Leo Ornstein's son Severo (best known as a computer expert who contributed to the early development of the Internet) is engaged in producing a printed edition of the compositions; a biography is underway and several pianists have taken up the challenge of his music.
In time Leo Ornstein will be recognized as a great American original.