When the Kennedy Center invites you to watch two would-be concert pianists perform a play they’ve written about their scale-slavery childhoods indentured to the keyboards and the careers they didn’t get, your first reaction isn’t exactly unbounded enthusiasm.

That’s one of the problems with being jaded. You miss a lot of fun.

2 Pianos, 4 Hands, the tenderhearted screwball brainchild of Canadian performers Ted Dykstra and Richard Greenblatt, turns out to be way more fun than it sounds and, though it’s never sentimental, far more touching than you’d expect. These two prove, gracefully, elegantly, with hysterical vignettes tinged with aches of regret, that dreams are worth chasing. And that your life doesn’t have to end when they escape you.

Granted, you’ll have to sit through an awful pun or two:

“How’s your back?”

“Not so good. How’s your Bach?”

“Not so good.”

But often as not, the follow-ups make the groaners worthwhile. The guy with the bad Bach, for instance: “I can play the Schoenberg,” he offers, uncertainly. “Nah,” replies his teacher, the guy with the bad back. “I’m in the mood for a melody.”

That the previous skit involves Billy Joel’s “Piano Man” only makes the instructor’s sly swipe at atonalism funnier.

That scene says a lot, actually: 2 Pianos, inspired by its creator-performers’ fraught backgrounds in classical piano, is nothing if not a brilliant fusion of sophisticated musicianship and middlebrow humor. And a large chunk of its appeal is in the way it builds joke upon joke, it’s got a great comic’s timing and a great conductor’s sure sense of rhythm.

Sitting at a pair of shiny 9-foot grands, or fooling around in the area between them, Dykstra and Greenblatt noodle on serious and silly works alike: If they’re not seguing from Bach’s D-minor Concerto to Hoagy Carmichael’s “Heart and Soul,” they’re embellishing a Mozart sonata with that inescapable “shave-and-a-haircut” riff or banging out Jerry Lee Lewis in a rehearsal room.

Between musical excursions both successful and less-than, they draw on a lifetime of dreams and disappointments, weaving memories of demanding parents and snotty concerto-competition rivals into an evening of both belly laughs and gut-wrenching reality checks. They impersonate themselves, the dessicated MC of a Kiwanis music festival, and a range of teachers, from the merely intimidating to the downright terrifying. Dykstra’s Sister Loyola, who’s clearly tried to teach key signatures to one dolt too many, is among the evening’s most priceless characters.

Driven at first by parental pressure, they metamorphose into neurotic arpeggio-playing adolescents and then temperamental, arrogant teens. It’s when they can taste success, when they can see a lifetime at the keyboard, when they begin to imagine their names on the Carnegie Hall playbill, that ugly reality intervenes: They’re talented, but not talented enough to make the cut.

Ultimately, 2 Pianos is about getting over that revelation, which is why it seems to connect even with those who haven’t encountered the institutionalized torture of music-theory classes and the unique horror that is ear training. Yes, Dykstra’s impossibly mobile face is no small part of what makes the show work, but what makes it memorable is the heady mix of bittersweet longing and common sense that underlies all the clowning.

Serious philosophical musing or offbeat comedy? Soft Click of a Switch, running in the off hours as part of Source Theatre’s Aftershocks series, is so incoherent in its windy self-importance that it’s impossible to be sure. The switch is connected to a homemade pipe bomb; its click is “soft,” maybe, because we’re apparently meant to sympathize with the two losers who’ve done the connecting. They’re living lives of quiet desperation, see, one’s divorced (or is he?); one’s crazy (or is he?), so it’s supposed to be at least touching and possibly even understandable that their frustration finds a violent outlet.

Carter W. Lewis’ inept, indecipherable one-acter is bad dramaturgical juju worked at the Mametic altar on which common vulgarity is made sacred and “meaningful”, which wouldn’t be nearly so troublesome if there were a point to be found anywhere in this indifferently directed, broadly acted mess. Johnny Ray Meeks manages to be almost charming as the more unbalanced, oops, I mean “refreshingly iconoclastic”, of the two, and the show takes on life briefly when they finally blow up one of those free-standing parking-lot photo processing joints and muse about how they’ve claimed victims (the pictures) without actual bloodshed.

But Scott Sparks, playing Willy Loman without the dignity, is as irritatingly mannered and twitchy as ever. Amateurish voice-overs and coarse sound design only underscore the realization that descends when the two finally walk into a kind of twilight zone to blow themselves up: This is 100 minutes of your life you’ll never get back.