FortiFi@

One way to teach opera is the “gradus ad Parnassum” method: start with baby steps, lengthen the stride and arrive gradually at the top floor. Another is to begin at the top floor, throw every imaginable sophistication and obstacle at students and appeal to their survival skills.

“Prelude to Performance,” a six-week summer school and workshop devised by the Martina Arroyo Foundation, seems to favor the shock value of sudden difficulty. Students are offering two operas, each daunting in its own way, in the Marian Anderson Theater at Aaron Davis Hall. Thursday it was Mozart’s “Così Fan Tutte,” which repeats this afternoon and has as its running mate Offenbach’s “Tales of Hoffmann” which opened last night and repeats tomorrow. The performances serve as final exam and graduation day all at once.

“Così” is opera’s encyclopedia of ensemble work: singers numbering anywhere from two to six faced with intricate, nakedly exposed and beautiful exercises in togetherness. The part of Fiordiligi includes two arias of vaulting athleticism, sustained energy and deep emotion.

Timing and mutual understanding drive “Così,” which is perhaps music’s most exalted example of conversation-as-music. Offenbach’s great opera is a challenge to concentration and stamina, although these performances use alternating casts, with two Hoffmanns per evening sharing a marathon part.

“Così” was directed by Ellen Rievman, who favored geometric physical comedy and occasional incursions into the audience. Musically, Thursday was not without its small defeats but owed ultimate success to its conductor, Willie Anthony Waters. Tempos, especially in the overture, were nicely calculated, and Mr. Waters’s small orchestra played not badly at all. In matters of clear rhythm and diction, the young singers were very well prepared, which is not to say they made consistent use of their preparedness. Recitatives could wander out of key, ensemble precision faltered as performers started to tire, and enthusiasms at times exceeded good sense.

I particularly liked the two male leads: Taylor Stayton as Ferrando and Joseph Flaxman as Guglielmo. Both voices have the glare of still-to-ripen instruments but exude good health and promise. Anthony Russell‘s Don Alfonso showed a muted but well-cushioned baritone and a suitable sense of restraint. Nina Riley was the kind of Despina one hopes for: diminutive, agile and with just the right clear, slender soprano voice.

Rachel Sliker handled Fiordiligi’s big moments fearlessly and with considerable command. Leandra Ramm’s Dorabella was frailer-sounding. I don’t know who put her up to playing the part for laughs, but it is not a good idea. Mozart’s female leads here are enigmas of both shallow and deeply suffering hearts. Comic bits in comedy must come of themselves. Truly funny characters find no humor in their own situations.