Possibly this performance was supposed to have included the complete act and the singer for Marke got ill and there was no replacement available. Alternatively, it may have been a concert that focused exclusively on Tristan, Isolde, and Brangäne (Melot is heard for one line just before the end) with Marke's long monologue left out intentionally. In either case, Barbirolli makes no cuts in the big love duet so we get to hear Mödl and Windgassen sing their roles without the tiresome cut so often heard. Both singers are in excellent voice, Mödl having no difficulty with any of the high Bs and Cs. She and Windgassen partner each other very convincingly. Shacklock's warm mezzo is heard to great advantage as Brangäne. Barbirolli builds everything to a incandescent fever.We hear the complete act through the duet and finish with the lovers' responses to each other after Marke's omitted monologue. Andy concludes the disc by bookending it with Isolde's Liebestod from the 1959 performance under Leitner (also available from Opera Depot). Mödl's voice was in more fragile condition by then, but she's still captivating. The sound is excellent.