Wagner famously broke off work on the Ring after Act 2 of Siegfried in order to write Tristan und Isolde, arguably his greatest score and, given that it rewrote the musical rule book, certainly his most influential. Whether by accident or design, the Proms approximated history by sandwiching its own very fine Tristan between the last two instalments of Daniel Barenboim's Ring.

Semyon Bychkov conducted the BBC Symphony Orchestra in a performance that was compelling if occasionally wayward. Bychkov's reputation as a measured Wagnerian is founded on his interpretations of early scores such as Lohengrin and Tannhäuser. In Tristan he allows himself more latitude with speeds, with surprising results. The slowly unwinding prelude led to a first act of gathering momentum that culminated in a confrontation between the lovers that was as swift as it was neurotic. Rather than lingering over harmonic progressions, O Sink Hernieder pulsated urgently. Mark's monologue felt too slow. And in Act 3, Bychkov ratcheted up the orchestral volume a bit too much, occasionally giving his singers a hard time. The BBCSO played it wonderfully well.

The cast was mostly impressive. Robert Dean Smith's voice has darkened a bit since I last heard him sing Tristan, though his accuracy, tirelessness and vocal ease remain staggering. Violeta Urmana was his Isolde, more convincing in rage than ecstasy, and not always in control of her upper registers. Mihoko Fujimura was the full-on Brangäne, Boaz Daniel the handsome, rather intellectual Kurwenal. There was a nicely sonorous Mark from Kwangchul Youn. Bychkov's decision to use men's voices from both the BBC Singers and Symphony Chorus meant that the Act 1 choruses really hit home for once.