Singers carry the day in S.F. Symphony’s ‘Fidelio’

In Thursday’s concert performance of “Fidelio,” the final element of the orchestra’s three-week Beethoven festival, the evening’s most rewarding aspects came from a terrific vocal cast, led by soprano Nina Stemme as Leonore and tenor Brandon Jovanovich as Florestan.

Beethoven famously struggled over “Fidelio” for years, and there are some who consider that for all its glories — including the time-stopping splendor of the Act 1 quartet, or the bravura arias for the two main characters — the piece never quite found the right balance of comedy and tragedy, or traced its way with complete assurance from one emotional peak to the next.

Stemme, in her first local appearance since her unforgettable Brünnhilde in the San Francisco Opera’s 2011 “Ring” cycle, sounded vibrant and full of fearless energy in what amounts to the title role of the piece.

Fidelio is the masculine name that Leonore adopts when she goes undercover, in male drag, to work as an assistant in the prison where her husband is being kept as a political prisoner (Stemme came onstage before the overture to establish the plot’s basic premise).

The rest of the cast was first rate as well, particularly tenor Nicholas Phan and soprano Joélle Harvey in the opening scenes — in which Beethoven seems to be setting out to write a “Magic Flute” knockoff before he remembers that he has weightier things on his mind — and bass Kevin Langan as the avaricious jailer Rocco.

After a festival that has witnessed thrillingly dramatic renderings of the “Missa solemnis” and Beethoven’s 1808 marathon concert, it was odd to find the opera providing less drama than either of its precursors.