Experimental Donizetti? Do those words ever belong together? Experimental or not, L’esule di Roma (‘The Exile from Rome’), premiered in 1828 at the Teatro San Carlo, is Opera Rara’s latest successful reclamation. It’s not just a curiosity but a piece Donizetti admirers may well take to heart. Experimentation was not unknown in bel canto mad scenes, though the composer’s innovations in this opera are often below the surface, according to annotator Roger Parker (also co-credited with the opera’s critical edition), during this period leading up to the 1830 breakthrough of Donizetti’s Anna Bolena.

The formal divisions so evident in Donizetti’s later opera are artfully blurred in a piece whose theatrical dynamism is consistently evident from the soliloquies to the choruses with greater veracity than Rossini’s freeze-frame technique of exploring a character’s inner thoughts. One aria, ‘Vagiva Emilia ancora’, has a lyrical outpouring from the opera’s anguished patriarch with interjections from his concerned daughter that fluidly evolve in a beautiful duet. Guilt in the extreme replaces the madness trope, and not in some delicate heroine but in the central bass-baritone character of Murena, whose fragmented vocal lines make him a forerunner to guilt-racked Boris Godunov.

The opera is uneven: some of the opening Act 1 music is routine. Donizetti also slips into sprightly though dramatically incongruous major-key moments, since audiences expected a varied menu of music. Non-scholarly listeners, though, are likely to hear a remarkable degree of dramatic integration. Expansive instrumental introductions that can meander in less inspired circumstances serve as an eloquent set-up for the emotional temperature of what is to come. Parker makes much of a terzetto (‘Ei stesso … La mia vittima’ – a trio with lots of musical accessories) replacing the usual Act 1 finale, which achieves a compelling dramatic focus for having fewer characters. Also the apparent lack of vocal athletes in L’esule di Roma meant that the out-of-plot set pieces in Donizetti’s Il paria (2/21), premiered a year later, weren’t necessary.

Domenico Gilardoni’s libretto is an elaborate, ancient-Rome variation on the Androcles and the Lion tale, in which the condemned Settimio is thrown into a lion’s den but survives because he once showed kindness to this particular animal. Along the way, he has a love interest, Argelia, whose father, the aforementioned Murena, had a hand in Settimio’s demise. While all ends well, Argelia has the last word with a triumphant high C that crowns the highly charged Act 2 finale – a reminder of how Donizetti could brilliantly meld theatrical meaning and vocal display.

Casting choices aren’t large opera house voices. Medium-weight tenor Sergey Romanovsky (Settimio) brings many expressive details to some of the opera’s best music and most introspective soliloquies. Much the same can be said of Albina Shagimuratova’s Argelia, who projects great emotional depth in the aria ‘Morte! Ah pria che l’una uccidi’ with less vocal grit and more clarity than in her Opera Rara outing with Il paria. Murena’s most tortured moments have Nicola Alaimo stretching the bounds of bel canto, though never neglecting the long vocal line. Supporting characters are all capably sung. The Opera Rara Chorus project the meaning of the words with great specificity.

Conductor Carlo Rizzi is no Donizetti apologist. Never are the orchestral gestures inflated to make the music seem imposing in the fashion of later composers. Lightness and firm but flexible pulse keep the opera moving along even in places where some conductors might favour more gravitas. One can’t describe the approach as historically informed, just meeting the score on its own terms. Perhaps the 1828 musicians knew they didn’t have to blast the listeners to operatic heaven: just sitting in the intimate, architecturally distinguished 1400-seat Teatro San Carlo – ‘The eyes are dazzled, the soul enraptured’, wrote Stendhal – they were halfway to heaven already.