What is it that makes certain pieces of music, certain dramas, not only have an immediate impact on an audience, but stick with people to become classics?

It could be that a certain tune is enough to make you remember an opera or symphony, a certain dramatic instance alerts the Broca’s area of your brain (that area that craves surprises and thus remembers what’s different) that makes you recommend a play or movie.

In my own entirely unscientific study of what connects with us, I’ve put together a checklist (feel free to disagree).

• For a movie comedy to be a hit (and to be considered funny), it needs at least three big laughs. It doesn’t matter if the rest of the movie trades in tickles. If it’s got those boffo payoffs, it’s successful.

Think of the 1998 film There’s Something About Mary. Lots of chuckles, but three huge laughs: the painful zipper moment, the awkward hair gel moment, the lovelorn tripping cripple moment. The result: $369 million in worldwide sales and, in the consideration of many students of film comedies (albeit those with short memories) one of the top five funniest films ever.

• For a ghost movie to be considered scary or a horror movie horrifying, it needs no fewer than two big scare moments or one scare and one shocking reveal (audiences for these films are less demanding and more willing to accept a suspenseful mood overall).

Think of 1999’s The Sixth Sense. It has a meditative and unquiet mood, but a couple of big audience-gasping moments. One occurs where spirits walk unseen in a hallway behind a room where the characters played by Bruce Willis and Haley Joel Osment are speaking. The other is the big reveal, when we realize the truth of Osment’s character’s line: “I see dead people.” The result: $678 million in worldwide box office.

• A Broadway musical needs perhaps one, but more probably two, big catchy numbers for it to become a hit;

• A romantic drama needs at least one tear-inducing moment (think of Ghost, when Patrick Swayze’s character touches Demi Moore’s toward the end – rivers of tears);

• A thriller needs at least one suspenseful chase or rescue;

• A mystery needs a true surprise as to whodunit.

You might have a long list of examples yourself for these and other genres. In the meantime let’s extend this idea to the classical world.

• An opera needs at least one killer aria (I’m thinking of aria-centric operas, of course, not Wagnerian musical dramas or contemporary works). You’d be right to argue that many operas by Mozart, Verdi and Puccini have more than two great arias, and you’d be right. But they were geniuses. And they knew the value of great tunes at a time when great tunes and great drama were pretty much of a pair.

But even in the sublime Marriage of Figaro with, to name but two amid a wealth of choices, “Porgi, amor” and “Dove sono,” Mozart’s contemporary audience latched onto “Non piú andrai,” which became the 18th-century equivalent of a radio hit, played in cafes and gatherings almost immediately upon the opera’s premiere. It was so familiar to everyone, in fact, that Mozart himself quoted it, quite wittily, in Don Giovanni, aware of the importance of hit tunes in even the most psychologically probing of operas.

I don’t mean to trivialize the dramatic scope of this or other great operas, or even symphonies such as Beethoven’s 5th, with its unforgettable opening, or his 7th, with its astonishing third and fourth movements. But think of works by gifted lesser composers, such as Massenet. Do people really know much more than the “Meditation” from his opera Thais? Or what about Delibes? Would Lakmé be remembered at all if it weren’t for its flower duet, “Dome epais le jasmin”? Would we remember Pachelbel but for his famous canon in D major?

The greatest works are filled with surprises, which is why they’re great, and why we remember them. The not-so-great but nevertheless long-remembered works have just those one or two or maybe three surprising moments. Which is why we remember those moments, but not the whole of the works themselves.