Arnold studied cello at the Maastricht Academy of Music and the Conservatorium van Amsterdam with Dmitri Ferschtman, and later in London with Christopher Bunting.

He studied conducting with Anton Kersjes at the Maastricht Academy of Music and took private lessons with Marcello Viotti, Jean Fournet and Graeme Jenkins.

He attended masterclasses with Jorma Panula in Moscow and Amsterdam, with Myung Whun Chung and Gianluigi Gelmetti at the Accademia Musicale Chigiana in Siena, Italy, and Diego Masson at the Darlington School of Arts in the UK.

He subsequently became the orchestra's principal guest conductor, and music director in 2012, until his resignation in March 2022, in response to the Russian invasion of Ukraine.

[1][2] Arnold has premiered several works of Canadian composer Tobin Stokes, including two of his operas, The Vine Dressers and Rattenbury.