As graduation ceremonies go, the Royal Ballet School’s annual matinée ranks among the most spectacular. It takes place at the Royal Opera House in front of an adoring parental audience, and although it serves primarily as a showcase for those passing out into the profession, it also contains spots for all 250 or so pupils, ranging in age from 11 to 19 and globally recruited, culminating in a glorious parade (called the défilé) of the entire establishment, drilled with a precision that reminds one of ballet’s miliary roots.