The old saw in show biz “Always leave them wanting more” is probably solid advice. Question is, where is that line and how do you know you’ve crossed it?

Feng Yi Ting, for instance, was there and gone much too soon. As operas go, it was less a full course meal and more of an amuse bouche. But it was perfect. And our bouche was definitely amuse-d.

Feng was an inspired introduction to classical Chinese opera. Director Atom Egoyan created a moving spectacle that tossed shadows, video projections, and lighting effects around the stage like confetti. We loved Guo Wenjing’s gorgeous, evocative music. As Diao Chan, Shen Tiemei seemed to inhabit the stage like a mythical creature of beauty and graceful movement. It was a production with a lot of moving parts that came together briefly and dispersed beautifully, but, even in its brevity, the opera sacrificed none of its emotional effect. Poet Robert Southey might have been talking about Feng when he wrote, “It is with words as with sunbeams. The more they are condensed, the deeper they burn.”

We could have listened to Cécile McLorin Salvant sing all night. A stray comment about her performance summed it up, “In 20 year’s time, you’ll say, ‘I saw her when.’ ” And Cécile’s pianist, Aaron Diehl? He’s a Julliard grad. He’s toured with the Wynton Marsalis Septet (Wynton calls him “The Real Diehl.”) The young pianist carries on a tradition of musical barnstorming as long as your arm, bringing hints of Scott Joplin, Jelly Roll Morton, Art Tatum, and Duke Ellington into his breathtaking keyboard work. I’d spend a long evening listening to Diehl anytime.

Some people felt that Hay Fever was a bit too long. I’m willing to bet that reaction was mostly a side-effect of trying to keep pace with the Bliss’ frenetic, unstoppable energy. These were rock-solid performances of a butterfly-weight farce. For the audience, it was a 500 meter dash among a very challenging field. You couldn’t help but be swept up in it all, largely because you were being seduced by these mad miscreants the entire evening.

From the start, Hay Fever had a flirtatious gleam in its eye and never let you forget it. When Sorel (the dazzling Rebecca O’Mara) complains to her brother, Simon (laugh-a-minute Tadhg Murphy) that the Bliss family are incorrigible, adding “I wish we were normal!” that line is more than a little undercut by Sorel’s provocative chaise-lounging when she delivers it. No doubt Sorel would know exactly what Dorothy Parker was talking about when she wisecracked, “Brevity is the soul of lingerie.”

Of course, every performance is well advised to fulfill that one audience expectation: that it have a discernible beginning, middle, and end. It’s that rich, chewy middle bit that’s often problematic. Sometimes dance (especially very technically complex pieces) can feel overlong if the audience is hoping for spellbinding passion but finding rigorous technique. Same with symphonies. And opera.

In this case, we’ll close with some words from Wolfgang Amadeus Mozart, who knew a thing or two about opera and symphonies (and hair styles). Here’s his take on brevity:

“My great-grandfather used to say to his wife, my great-grandmother, who in turn told her daughter, my grandmother, who repeated it to her daughter, my mother, who used to remind her daughter, my own sister, that to talk well and eloquently was a very great art, but that an equally great one was to know the right moment to stop.”