In just under an hour and a half Die Walküre. In the Uk, it's on BBC Radio 3 on 90-93 FM or Sky Digital 853 or on t'internet.
Ooh, and look who's in the 'Round Table' in the second interval.
Other radio stations can be found here.
Update:
Sieglinde's Diaries reports from Tuesday's performance
Faust. That orgasmic Die Walküre will almost certainly include Plácido Domingo as Siegmund, who is going straight to hell after he dies at age 127. No other explanation is more plausible than a bargain with the devil, and Im telling you, I had to pick my body up from the floor after being struck down with a lavish, sexy, heroic high A on Wälsungen-Blut!, the longest Ive witnessed him hold it, to finish a magnificent Act I (currently my favorite act of all of Wagner). It seems hes just about ready to caravan with Giordani and Licitra for a "Three Tenors, Next Generation" tour. He tires a bit in the middle of the first act, but listen, I get tired just ascending to the family circle from the plaza; then he picks up a vessel and drinks devil water and bam! the tenor is back, more frightful than ever. The Wälse! is more than solid; the Notung! sags a bit; but the Wälsungen-Blut! must have been lipsynched from a Melchior recording. There's just no other way to explain. Elsewhere, he is pure Siegmund, 23 years old and thoroughly jock-y.