He studied cello with Timothy Hugh, Steven Doane and Johannes Goritzki at the Royal College of Music and at the Robert Schumann Hochschule, Düsseldorf respectively.

[3] Master-classes with Mstislav Rostropovich, Janos Starker and Aldo Parisot led him to France, Italy and North America.

He studied conducting with Professor Thomas Gabrisch[3] in Düsseldorf and worked closely with Yan Pascal Tortelier as his assistant conductor, among others with the National Youth Orchestra of Great Britain.

[6] In 2009, Shelley became Artistic Director of the Zukunftslabor project of the Deutsche Kammerphilharmonie Bremen[7] with whom he went on to win the 2012 Echo Klassik award in the category of Youth Engagement.

[8] In September 2009, Shelley was named the youngest ever Chief Conductor of the Nuremberg Symphony Orchestra, with an initial contract of four years.

[9] During his tenure the orchestra dramatically increased their international touring, travelling to China, Italy, the Czech Republic and Austria.

[19] In October 2013, the NACO announced the appointment of Shelley as its youngest ever Music Director, succeeding Pinchas Zukerman as of the 2015–2016 season, with an initial contract of 4 years.

[27] In the spring of 2019, Shelley led the NAC Orchestra on a landmark European tour in celebration of the National Arts Centre's 50th Anniversary.

Entitled CROSSINGS, the tour included eight concerts featuring four internationally renowned Canadian soloists: Jan Lisiecki, James Ehnes, Erin Wall and David D Q Lee.

In April 2022 Shelley led the orchestra on tour to New York's Carnegie Hall with a flagship programme entitled 'Truth in our Time'.

The tour concerts, which probed important cultural questions through their choice of music, included the world premiere of Philip Glass's 13th Symphony, commissioned by Shelley and the NAC in memory of the life of ABC News anchor Peter Jennings.

[38] 2010 Nürnberger Symphoniker Live in Prag (Nürnberger Symphoniker and Oliver Triendl on Colosseum Records) 2011 Nürnberger Symphoniker Live in Wien (Nürnberger Symphoniker on Colosseum Records) 2014 Escape to Paradise (Stockholm Philharmonic and Daniel Hope on Deutsche Grammophon) 2015 Brahms Violin Concerto/ Double Concerto (Nürnberger Symphoniker, Eric Schumann, Mark Schumann on Berlin Classics) 2015 Peter and the Wolf in Hollywood (Bundesjugendorchester, Alice Cooper on Deutsche Grammophon) (ECHO Klassik 2016) 2017 Life Reflected (National Arts Centre Orchestra on Analekta) 2017 Encount3rs (National Arts Centre Orchestra on Analekta) 2018 New Worlds (National Arts Centre Orchestra on Analekta) 2018 Bounds of our Dreams (National Arts Centre Orchestra on Analekta) 2019 American Recorder Concertos (Copenhagen Philharmonic, Michala Petri) 2020 Clara, Robert, Johannes: Darlings of the Muses (National Arts Centre Orchestra, Gabriela Montero on Analekta) 2021 Clara, Robert, Johannes: Lyrical Echoes (National Arts Centre Orchestra) 2023 Clara, Robert, Johannes: Atmosphere and Mastery (National Arts Centre Orchestra on Analekta) 2023 Clara, Robert, Johannes: Romance and Counterpoint (National Arts Centre Orchestra on Analekta)