O magnum mysterium:

Edited by Cáitia mendes for CPDL

Original version is for organ, choir, soprano solo and intruments.
The soprano solo, and instrumental parts start at bar 35, Ave Maria.
The organ part continues throughout the piece, and the choir is active from bar 1 to bar 34.
The instruments listed are (in Potuguese): Fagotilho, Violino, Baixão, and Guyão.

The version here is an arrangement for four recorders by DSH.