Choir Concert with Legendary Conductors Anton Armstrong and André Thomas. Sunday, May 21, 3:00 p.m., Sanctuary. Featuring the BMPC Sanctuary Choir and Children and Youth Choirs, Singing City and the Singing City Children’s Choir, and the Chamber Orchestra of Philadelphia. Tickets: $20 for preferred seating; $15 for general admission; $5 for students. Available for purchase from Singing City, 267-519-5321.