Rossini’s Ermione is the 19th century’s finest operatic treatment of a subject drawn from Greek tragedy. Not until the appearance of Richard Strauss’s Elektra in 1909 would there be a work to surpass it. Not that anyone was aware of the precedent. What happened in Naples in the spring of 1819 to cause a shroud to be thrown over this nascent masterpiece is one of the unsolved mysteries of operatic history. “I fear the subject matter may be too tragic,” Rossini told his mother.

Rossini knew the work was a masterpiece and kept it by him for the rest of his days. It would not be seen again on stage until the Pesaro Festival’s revival of 1987. An Erato studio recording conducted by Claudio Scimone had been made the previous year; it remains in the catalogue, a plausible though at times over-decorous account of the score featuring Cecilia Gasdia as Ermione.

The real truth about Ermione was finally revealed in London in 1992. Mark Elder conducted the OAE and a cast which included Anna Caterina Antonacci in the title-role in two concert performances which decisively returned Ermione to the operatic agenda. The new Opera Rara recording was made in London’s Henry Wood Hall in March 2009. It is a striking achievement, superior in most respects to the 1986 Scimone, though not one which would outstare the Elder if the tapes of that performance were ever to be released.

The new recording runs at white heat whenever Colin Lee’s Orestes is on stage. This is a fierce and brilliantly realised portrait of the erotically obsessed and emotionally unstable fall guy who reaps the tragedy’s final whirlwind. His cousin Pilade is sung with a comparable mastery of the rhetoric of the role by Bülent Bezdüz, a model of comprimario playing. Pyrrhus, who holds hostage Andromache, the woman he loves, and her young son whom the Greeks fear and want, is the tyrant of the piece. He is also its principal victim, slain by Orestes’ confederates at the behest of Ermione, who instantly abjures the act.

Patricia Bardon paints Andromache’s grieving mood most effectively in the opening scenes but the voice can become edgy and lose line under pressure. Carmen Giannattasio’s Ermione has no such problems. Rossini’s word-setting in the great scene in Act 2, where Ermione agonises over the deed she has commissioned Orestes to enact, is Shakespearean in its art and eloquence and Giannattasio is the mistress of every phrase.

Orchestrally, Ermione offers its own special sound palette, spare and arresting. Many of the motivating rhythmic figures are “from stock”, as it were, but given a keen focus they work with the same propulsive force which is the mark of early and middle-period Verdi.

There is a small but fascinating chorus role in Ermione, not least in the groundbreaking overture where the cries of Trojan prisoners are heard. The Opera Rara chorus disappoints, indeterminately recorded and sounding more like a conservatoire choir than players in a music-drama.

This is a minor drawback. A larger one – occasional passages of slackening tension in the performance as a whole – can probably be traced to the exigencies of the studio process. Most of these episodes bear the mark of frequent and fiddly editing.

The set is none the less a notable achievement, purposeful and bold, and the documentation is first-rate. A richly informative monograph on Ermione by Jeremy Commons is particularly worthy of note.