Nana Vasconcelos and Collin Walcott
Public Theatre
NY, NY
March 21, 1980
as broadcast on NPR's "Jazz Alive!" (see note below)

Total time: 18:24

01 intro by A.B. Spellman (1:59)
02 (5:37)
03 (4:09)
04 (6:29)
05 outro by A.B. Spellman (0:09)

notes:
FM broadcast (circa 1980-1981) > Rotel receiver > Akai cassette deck > Maxell UD90 cassette (Dolby B) > Sony TC-WR635S cassette deck (refurbished 2021) > PC > Goldwave > Flac (2021)

The other performances mentioned by A.B. Spellman in his intro can be found here:
http://www.dimeadozen.org/torrents-details.php?id=706683
http://www.dimeadozen.org/torrents-details.php?id=702098

This performance is not listed in the following lists of the artists' official releases:

https://en.wikipedia.org/wiki/Nan%C3%A1_Vasconcelos
https://www.discogs.com/artist/266172-Nan%C3%A1-Vasconcelos
https://en.wikipedia.org/wiki/Collin_Walcott
https://www.discogs.com/artist/315689-Collin-Walcott