The school has four music teachers and several peripatetic teachers, and 300 pupils learn a musical instrument. The biggest problem has been obtaining sufficient instruments. "Many pupils come from homes that can't afford it, or where there's no tradition of making music," she explains.
There are Government schemes that can help, but Elizabeth has found them difficult to access and has turned to charities such as the Rayne Foundation.
Music has enriched lessons in other parts of the curriculum, including IT, maths and science: "For some youngsters, sitting behind a desk is boring.
But music gives less able pupils an opportunity to achieve." The range on offer is impressive - African drumming, salsa percussion and jazz workshops.
St Marylebone's is surrounded by private schools, and Elizabeth feels music bridges the gap between haves and have-nots: "Private education gives children definite advantages; I want my pupils to have a share in these and music can help."