IL TROVATORE, Unrated, 1985, in Italian with subtitles, 145 minutes, Home Vision, $39.95.

It is unlikely that anyone will ever produce a theatrically convincing performance of this potpourri of a Gypsy's curse, a troubadour's hopeless love, a soprano fleeing to a nunnery, men pitted in mortal combat not knowing they are brothers, and vast armies that never seem to do anything but run around singing about how fierce they are. Its theatrical implausibility -- the fact that it is a distillation of the most extreme Romantic poses and attitudes -- makes "Il trovatore" a perfect show for the Arena of Verona, an ancient Roman amphitheater with remarkable acoustics and rudimentary stage equipment, where no opera looks really convincing though they often sound good. This one generally sounds extremely good, with such stars as Rosalind Plowright, Fiorenza Cossotto, Giorgio Zancanaro and Franco Bonisolli, who sang the title role for the Washington Opera a while back and is its leading living exponent. Bonisolli's big number, "Di quella pira," is so well done that the audience makes him repeat it (a bit more hoarsely the second time). The costumes look good on videotape, and who needs convincing sets or stage direction when everyone is (most of the time) in such good voice?