Orquestra Sinfônica e Coro do Teatro Municipal do Rio de Janeiro
Marcel Wengler, regente
An LP of a live performance at the Teatro Municipal in Rio de Janeiro from November 1978. This is the only recording I know about of the 2nd Sinfonietta. Thanks to Wellington & the crew from Brazilian Concert Music for this.
The disc contains live performances of the Sinfonietta #2, Choros #10, and André Kostelanetz's super-rich and super-fun arrangement for cello & orchestra of the Song of the Black Swan (O Canto do Cisne Negro).
You can download this LP in MP3 format from the Brazilian Concert Music blog.