As pianist he has performed, broadcast and recorded around the world with leading orchestras and conductors including Vladimir Ashkenazy, Pierre Boulez, Sir Adrian Boult, Colin Davis, Mariss Jansons, Gennady Rozhdestvensky and Kurt Sanderling.
During the fortieth anniversary of Sergei Rachmaninoff's death he became the first pianist ever to perform the composer's complete solo piano works in concert.
He has held positions of Associate and Principal Guest Conductor with the London Mozart Players in a close relationship of over twenty years.
He has toured with them to Japan, Korea, Germany, Sweden, Italy, the Netherlands, Ireland and to the Prague Autumn Festival, and has made many recordings with them.
A documentary on Ravel made in 1998 by the Australian Broadcasting Corporation, featuring Shelley as conductor, pianist and presenter won the Gold Medal for the best arts biography of the year at the New York Festivals Awards.
In the latter film, directed by Tony Palmer, Ben Kingsley played the part of Dmitri Shostakovich, miming to Howard Shelley's piano.