Stefan started his violin studies with Fiona Giambra later obtaining his LRSM under tuition of Mario Bisazza. In 2017, he graduated from the University of Malta under the tutelage of Natalia Filipenko and later obtained a Master’s Degree at the Trinity Laban Conservatoire with Clare Thompson as a TL Scholar. Since 2010, Stefan has been active in the musical scene and has won several competitions and awards. He has also performed as a soloist with Malta Youth Orchestra (MYO) and MPO.
As an orchestral musician, Stefan played with the European Union Youth Orchestra, the Mediterranean Youth Orchestra and Commonwealth Youth Orchestra. He was the leader of the MYO and of the TL Symphony Orchestra.
Calleja has been supported by the BOV Joseph Calleja Foundation, Janatha Stubbs Foundation, the MPO and the Malta Arts Scholarships in his studies.
Stefan currently teaches at the Malta School of Music and works with Teatru Salesjan, contributing towards the education of young musicians.