Oreste made his operatic debut on 25 February 1945 as Turiddu in Cavalleria Rusticana at the Radio City Opera House in Ħamrun (Malta).
[4] In 1950 he moved to the United Kingdom and sang principal tenor roles with the Carl Rosa Opera Company, later with Sadler's Wells (1952) singing Turiddu, Mario Cavaradossi, and Rodolfo in Luisa Miller.
A contract with Paramount Pictures led to the leading role of François Villon in the 1956 film version of The Vagabond King.
He sang opera at Las Vegas and the Hollywood Bowl and appeared on NBC TV in pioneering productions of Madame Butterfly, La traviata and Rigoletto.
His retirement was mainly due to heart problems after being told by doctors that he might die on stage if he continued his singing career after the age of 40.