Bernstein studied with Alexander Brailowsky, Clifford Curzon, Jan Gorbaty, Nadia Boulanger, and George Enescu.

In 1969 he made his debut with the Chicago Symphony Orchestra,[5] playing the world premiere of Heitor Villa-Lobos's Concerto No.

He ceased performing in 1977 in order to concentrate on teaching, composing, and working in other creative outlets; he did not tell anyone that his farewell recital would be his last.

Bernstein has composed music ranging from teaching material for students of all levels to sophisticated concert pieces.

[7] In 2020, Seymour recorded a series of pedagogical lessons for tonebase piano covering works by Beethoven, Chopin, Mozart, Schumann, and technical exercises like arpeggios.