He desired to resurrect the original tone and range of the saxophone as intended by its inventor, Adolphe Sax.

He lectured and served as a guest professor in such cities as London, The Hague, Hamburg, Düsseldorf, Helsinki, Rochester, Stuttgart, Lyon, and Oslo.

In 1995 he played the world premiere of Dimitri Terzakis's saxophone concerto, which was broadcast live to 27 nations.

Other composers who have written works for Kelly include: Samuel Adler, Kalevi Aho, Osvaldas Balakauskas, Jürg Baur, Erik Bergman, David Blake, John Boda, Thomas Böttger, Herbert Callhoff, Michael Denhoff, Violeta Dinescu, Brian Elias, Anders Eliasson, Werner Wolf Glaser, Sampo Haapamäki, Ingvar Karkoff, Maurice Karkoff, Tristan Keuris, Hans Kox, Nicola LeFanu, Otmar Mácha, Tera de Marez-Oyens, Miklós Maros, Gérard Masson, Roland Leistner-Mayer, Krzysztof Meyer, Gráinne Mulvey, Pehr-Henrik Nordgren, Enrique Raxach, Uros Rojko, Jan Sandström, Sven-David Sandström, Leif Segerstam, Manfred Stahnke, Dimitri Terzakis, Stefan Thomas, Friedrich Voss, and Iannis Xenakis.

Kelly met his wife Kristin, a physician, at a concert in Germany.