The mission of the Commonwealth Youth Choir is to use music as a means of international dialogue, knowing no boundaries.

The Commonwealth Youth Orchestra & Choir brings together communities across the Commonwealth through music, transcending all cultural, political, social and economic boundaries. It delivers its mission through a three-point plan: "Engage-Educate-Empower" and through its pan-Commonwealth music activities and its unique education initiative - the Commonwealth Music Partnership - which is linking all the choirs, orchestras and music schools in the Commonwealth for opportunities exchange and collaboration.

Her Majesty The Queen, Head of the Commonwealth, is Diamond Jubilee Patron 2012 of The Commonwealth Youth Orchestra & Choir.

As part of the Commonwealth Diamond Jubilee Legacy, the Commonwealth Youth Orchestra & Choir established the Commonwealth Children's Orchestra & Choir and the Commonwealth Orchestra, which creates platforms and employment for musicians in all 54 countries of the Commonwealth.

St. Mary's children participate in regular workshops with the Commonwealth choir and have had the opportunity to sing at the The Royal Military Chapel (The Guards' Chapel) with the Scot's Guard.