Alfred J D’Souza, the founder and conductor of The Stop-Gaps Choral Ensemble, is about to begin rehearsals at a Bandra school hall. A fly on the wall, we take a seat to watch and listen. At the centre governing the pitches, the choirmaster is dressed in jeans and Birkenstocks. But nothing is casual about D’Souza when he conducts the choir. With animated precision and grace, he is the infectious source of the choir’s rising fervour. The music is festive and playful, interspersed with crescendos and gentle falls. With a final swoosh of the hand, the song is complete and the conductor is pleased.

The group practises for its annual concert, A Festival of Festive Music, which will take place tonight and tomorrow at The National Centre for the Performing Arts (NCPA) along with over 15 other choirs from across India. It’s the 40th edition of the festival, and the fact of this special milestone seems evident in the manner of the rehearsals; or perhaps the passion is due to the standard D’Souza holds his pupils to. If you know ‘Alfie’, you’ll know that he can be quite strict, but his chiding is always marked by familiarity, especially if you catch a smile escaping from his lips; his choir loves him. “When it’s practice time, we practise,” he chuckles, “After all, the memorable concerts are the ones that give you the most trouble.”