Heitor Villa-Lobos, Author of the Nisi Dominus

In his entertaining Lies: A Diary, 1986-1999, Ned Rorem writes this entry, dated "Nantucket, 20 November, [1989]":

In a rented car that brought us here yesterday the radio played a Vivaldi Psalm for alto, in several movements, called Nisi Dominus. But one of the movements isn't Vivaldi's, it's by Villa-Lobos. Sly fox: his famous fifth Bachianas Brasileiras isn't filched from Bach at all, but note for note from Vivaldi. Yes of course it's his too, like Borges's Don Quixote.

I guess Rorem means the fourth movement "Cum dederit", from Psalm 126. Listen for yourself:

   

Rorem's Borges reference is to the 1939 story "Pierre Menard, Author of the Quixote", an early masterpiece of post-modernism.