In the April 1 issue of The International New York Times David Belcher persuasively argues the considerable artistic and economic merits to performing opera in concert. On Thursday evening Amanda Forsythe and David Hansen in evening dress sighing, swooning, conniving and triumphing as Poppea and Nerone with the Boston Early Music Festival Chamber Ensemble at the Morgan Library proved his points in a deliciously involving musical and dramatic experience. Who needs sets and costumes anyway?  

It’s difficult to imagine how a fully staging could surpass those compelling excerpts but many will travel to Boston in early June to discover just that when the centerpiece of the biennial Boston Early Music Festival will be a rare cycle of all three of Monteverdi’s surviving operas produced by the same production team over a single week.

However, the first half of the program, the final concert in the BEMF’s indispensable annual three-concert series at the Morgan Library which was repeated Friday in Boston, provided New Yorkers with a scintillating preview as the two protagonists of the festival’s L’Incoronazione di Poppea performed four extended scenes, nearly all the music composed for early opera’s most memorable, least admirable couple.

Having captured the attentions of Rome’s emperor, the ambitious Poppea uses all her many charms to persuade Nero to remove the obstacles—namely, his wife Ottavia and the philosopher Seneca—who stand between her and the throne. As the title suggests, she succeeds and the opera concludes with the exultant pair in the score’s greatest hit “Pur ti miro,” a spellbinding duet likely not written by Monteverdi.

That both Forsythe and Hansen were impossibly good-looking, tall and slender added to the dramatic frisson of the scenes. Happily, too, they know very well how to sing early 17th century opera where the text (by Giovanni Busenello) is as important as the music. Unofficial queen of Boston’s bustling Early Music scene, Forsythe, who appears far too rarely in New York, again showed why she is one of America’s premier baroque sopranos.

While many who sing this music wield severely compromised high notes which they peck at with a gratingly white straight-tone, her upper register positively glows before it descends into an interestingly dusky middle range which she exploited with artful cunning to manipulate the besotted Nerone. She was unafraid to (sparingly) use vibrato to subtly color her music.

Her Italian too was pungently inflected with subtle guile. One can never be sure whether Poppea even loves Nerone: it’s hard to shake that enduring image from Jean-Pierre Ponnelle’s film where Rachel Yakar sings most of the final duet to her new crown rather than to Eric Tappy as her husband.

Entrancing in her clingy aqua gown, a confidently self-aware Forsythe played a seductress on-the-make who reveals little of her true feelings. Surrounded by the seven instrumentalists, she planted herself firmly at the music stand at the center (although she and Hansen rarely referred to the score). While Hansen circled and ranted and pleaded, she remained mostly implacably still. Only when he declares that she will be Empress did she see the prize within her grasp and feel free to swan about the stage.

Although Forsythe and Hansen interacted beautifully together enjoying a palpable rapport, their voices didn’t blend together as perfectly as have other couples but at least they intertwined at the correct pitches. Just when one believed the bad-old days of tenors like Jon Vickers roaring heroically through Nerone’s transposed music were past, one notes with incredulity—that as recently as last summer the Paris Opéra presented Robert Wilson’s new production of Poppea featuring a tenor—Jeremy Ovenden—as the emperor.

While more often than not Nerone is now cast with a woman, over the past several decades a few brave counter-tenors have ventured the part. David Daniels proved wonderfully effective, but both Philippe Jaroussky and Max-Emanuel Cencic were inexorably challenged by the cruelly high tessitura.

Despite his occasionally vertiginous high notes, Hansen, an Australian countertenor, too was sometimes taxed by Nerone. The more dramatic music, the more the voice became screamy. Otherwise it’s an impressively large, secure if occasionally swallowed sound, although its plumminess can sometimes occlude his diction. A highly kinetic artist, Hansen brought the petulant willful emperor vividly to life through his bewitching interaction with Forsythe, superbly accompanied by the ensemble led by BEMF co-musical-directors Paul O’Dette and Stephen Stubbs.

I had more reservations about Hansen during the concert’s less compelling but still enjoyable second-half: a miscellany from thirty years of Handel. Whereas Forsythe paired a shimmering “Schönste Rosen,” a souvenir from the 2013 BEMF production of Almira, with a piquantly dazzling “Da tempeste” from Giulio Cesare, both of Hansen’s selections were “up-tempo” showpieces: “Torni pure” from the rarely performed serenata Il Parnasso in festa and the oft-heard “Dopo note” from Ariodante (taken at a surprisingly deliberate tempo.)

Although the florid singing revealed a firmer control than was sometimes the case on his recent Rivals CD, he would still occasionally swoop up to ungainly (and overly loud) high notes. In fact, throughout the evening there was less quiet, nuanced singing than one might have liked. A recent broadcast of Hansen singing David in Handel’s Saul from Vienna under Nikolaus Harnoncourt revealed that he has the potential to be a more sensitive artist; however, his tendency remains to showboat and dazzle.

Still, much of Hansen’s singing–particularly in the Monteverdi and in the sizzling duet from Ariodante that concluded the program–suggested that he’s made enormous strides since I last heard him nine years ago in what was (I believe) his only previous appearance in New York as a callow, dazed Solomon in Handel’s oratorio under René Jacobs at Alice Tully Hall.

A less satisfying glimpse into 17th century Venetian opera was on show at Zankel Hall on Tuesday evening when “L’Amore Innamorato” was given by L’Arpeggiata as the opening concert of Carnegie Hall’s ambitious “Before Bach” series. I have long had mixed feelings about Christina Pluhar’s plucky ensemble and its quasi-jazzy renditions of early music—I skipped next night’s “Improvisations on Purcell” concert because I hated the recent CD which featured the same approach to the English master’s music. However, the chance to hear a rare US appearance by the splendid Catalan soprano Núria Rial singing excerpts from rarely-performed works by Cavalli proved irresistible.

However, the short (barely over an hour) concert disappointed—the selection and presentation of the arias from six operas seemed to have little coherence, and Pluhar’s realizations nearly always featured lots of cornetto and percussion, both of which were jarring. Rial has a soft-grained, beautifully radiant voice which always ravished the ear, but she did little with the important texts and scarcely differentiated between the bewildered nymph Calisto and the randy page Nerillo and the grieving Trojan princess Cassandra.

Only in the final selection, Hecuba’s anguished monologue from La Didone, did we finally catch a glimmer of specific dramatic commitment. Two encores which had nothing in common with the rest of the program were peculiar choices.

New York’s current flirtation with early opera continues on Sunday afternoon at Carnegie Hall when Les Violons du Roy and La Chapelle de Québec perform an all-Purcell program including a complete Dido and Aeneas starring Dorothea Röschmann and Henk Neven.

Those who missed the Forsythe-Hansen’s previews won’t have to wait until June to sample their Poppea and Nerone: they will be paired again on April 24 and 25. Their music however will instead be by Handel when Boston Baroque performs that composer’s great early opera Agrippina, and they will be joined by Marie Lenormand as Ottone and Susanna Phillips in the title role.

Even those not on the east coast this spring may still revel in the BEMF doing 17th century opera by diving into its wondrous new recording of Steffani’s 1688 Niobe, Regina di Tebe, the surprise hit of its 2011 festival. Philippe Jaroussky, who starred in that revival repeats his sterling Anfione.

Meanwhile former Niobe Forsythe was “demoted” to the role of Manto so that Karina Gauvin could be brought in to sing the titular queen which she does nobly. Niobe is a complex, demanding work of nearly for hours but its extraordinary riches repay the effort. However, Forsythe fans should not be discouraged: Thursday evening’s program notes included some grand news: she will be releasing her first solo CD later this year—Handel arias on Avie!