It appears that Beck's short handful of festival gigs in Europe had ended, so he "sat around in Spain for five days," as he tells the audience when he apologizes for being rusty. To end his vacation, he opened for Sonic Youth, alone, doing his solo acoustic thing. (He had used a band on the other festivals, but I guess they went home.)
Beck's set was apparently broadcast on the radio. Beck explains the whole story behind "Truckdrivin Neighbors" before a superb version of the song (though he does flub the words a bit). Nice set overall, but way too short (25 minutes seems low, even for an opening act!).
I'm unsure if I have the best quality version of this tape...as it's a little warped and fuzzy. We have this noted as an A+ sound too, which mine is not.