During frequent visits to his father's workplace at the Commerce movie theatre on Strada Reale in Valletta, Pace became enamoured of the impromptu style of live musical accompaniment played by the resident quartet during screenings of silent films.

With Malta under near constant bombardment by the Axis powers, Pace was appointed Shelter Supervisor with responsibility over more than five hundred refugees, and subsequently took a position as a clerk in the Royal Air Force offices in Valletta.

[4] The Pace family abandoned their Valletta home after it was demolished by aerial bombardment, and relocated to the town of Sliema on the opposite shore of Marsamxett Harbour.

[4] By the time he was 20, Pace had composed suites for piano, violin and violoncello, followed by numerous cantatas, orchestral and chamber music, sacred hymns, two ballets, band marches, concertos, and an oratorio.

His 1931 composition, Maltesina, a musical fantasy based largely on traditional Maltese folk tunes and għana, was premiered by the Highland Fusiliers' Band in Palace Square.

His first opera, Caterina Desguanez (1965),[5] libretto by Ivo Muscat Azzopardi, tells the story of a Turkish slave who falls in love with his master's daughter.

His works have also been played in the United States, Russia, England, Wales, France, Italy, Germany, Norway, Sweden, Poland, Egypt, India and Argentina.