I'm afraid that the Barber of Baghdad left me pretty cold. It's not particularly long, but the first act seemed to go on for hours. Most of the singing was done by the tenor (Nureddin) who, alas, seemed to have a load of plums in his mouth. The arrival of Bostana to tell him that his girlfriend will see him didn't do much for me, and the arrival of the comic and very garrulous barber did even less. In the second half, bizarrely, Nureddin hardly had anything to sing and was hidden in a trunk for much of the time, but the music was a bit better, the girlfriend (Margiana) was good and some of the comic business was mildly amusing. Grove Opera claims that this work influenced Meistersinger, but I found that very difficult to believe. German romantic opera? Give me Weber, Marschner, Lortzing or early Wagner over Cornelius every time.
Everything else (except the weather) was very enjoyable. Luisa Miller was very well done and Alcina, though long, held the attention, even in a rather-too-minimalist staging. Trouble in Tahiti was very enjoyable, and the serious bits were quite moving. The Sam and Dinah were also the singers in Arias and Barcarolles. The band (string quintet with double-bass, plus two percussionists) were on stage, and the singers moved around a bit, but it wasn't really staged. I liked most of the music, and it ended with a sort of nocturne.
The Viardot show, about 90 minutes, consisted largely of songs composed by her, often with words by Russian writers (she lived in a sort of ménage à trois with Turgenev and her husband). The exceptions were composed by her father (Manuel Garcia I), Gounod (she premièred the role of Sappho in his opera of that name) and Meyerbeer (she was the first Fidès in Le Prophète). The singer was a Bulgarian mezzo who had sung the role of the duchess in Luisa Miller - she was good, as was her accompanist, the songs were mostly enjoyable, and there was a judicious narration about Viardot's life and times by a scholarly conductor (Julian Smith).