I don't have a clue where I got this tape. I've had it since about 1985.

SONY UCX-S 60 > Fostex X-12 4-track > Olympus LS11 (wav 24/48) >
USB 2.0 > hard drive > Audio Cleaning Lab 12 (slight hiss reduction,
normalize, track split, downsample) > wav (16/44.1) >
flac level 8 > this !!!

Possibly:

Stevie Ray Vaughan: Double Trouble Demos (w/ Lou Ann Barton)

Electric Graceyland, Austin, TX, September 1979

01 Rude Mood
02 Dirty Pool
03 Live Another Day
04 You’re Gonna Miss Me, Little Baby
05 Pride and Joy
06 Love Struck Baby
07 Natural Born Lover (Lou Ann - voc)
08 Ti-Na-Nee-Na-Nu (Lou Ann voc)
09 Scratch My Back (Lou Ann - voc)

There was also some stuff from a 1983 Austin City Limits show on there. I didn't include it, because it's been around the world a hundred times already.