He served as Reid Professor of Music[1] at the University of Edinburgh and has also taught at the Hochschule für Musik, Theater und Medien Hannover.

His compositions include the opera The Electrification of the Soviet Union,[8] Concerto for Flute and Chamber Orchestra[9] commissioned by the City of London Sinfonia, I am Goya,[10] Remembering Esenin,[11] and Birth of the Beatles Symphony.

[12] Osborne retired from his Edinburgh University position in 2012, and is now working internationally as freelance composer, arranger and aid worker.

[17] He has worked as visiting lecturer and examiner also at Harvard, UCLA, CalArts, Gedai and Toho Gakuen School of Music, Oxford, the Sorbonne and Bologna.

Osborne has collaborated with directors Lenka Udovicki, Peter Sellars, David Pountney, Michael McCarthy and David Freeman, and with writers Samuel Beckett, Craig Raine, Eve Ensler, Jo Shapcott, Howard Barker, Ariel Dorfman, Tena Štivičić and Goran Simić, with notable actors Vanessa Redgrave, Annette Bening, Lynn Redgrave, Amanda Plummer, Rade Šerbedžija, Simon Callow, Ian McDiarmid and Janet Henfrey, also with artists and designers John Hoyland, Dick Smith, George Tsypin, David Roger, Bjanka Adzic Ursulov and Peter Mumford.

[30][31] Osborne has worked actively in human rights initiatives, Workers' Defence Committee in Poland (1970–89), Citizens' Forum and the Jazz Section with Václav Havel in former Czechoslovakia (1987–1989), for Syrian refugee support organisations.

Pepper's Lonely Hearts Club Band for the ‘It Was Fifty Years Ago Today’ concerts with the Bootleg Beatles performed to capacity crowds at the Royal Albert Hall[38] and Echo Arena Liverpool.