I am positive that tengo (which did NOT have a name when we performed it) was not a studio track so I'm going to go out on a limb here and say that it must have been another sound-check track. The vocals most likely were from the same soundcheck. Massimo probably lipsynched to the track in the studio [for the video]. I'll have to rent it now! As a matter of fact, I'll lay money on it. Soundcheck track. Boom. Done.
[Boston, February 19, 1988] At rehearsal we performed "Tengo Na Minchia Tanta", "T'Mershi Duween", "Why Don'tcha Do Me Right", "Brown Moses", "Sinister Footwear", "Sy Borg" and "Token Of My Extreme". "Sy Borg" was one we had never played before, and fortunately I knew the chords, so we were able to do a reasonable version of it and give Frank the overriding feeling that it was a doable song, which is good because it's a very nice song.