‘All I wanted was the pleasure of mixing things together to see whether or not they were miscible,” François Truffaut once said of his 1960 film “Shoot the Piano Player,” which followed his enormously successful feature debut and New Wave standard-bearer “The 400 Blows.” His second film boldly set cheeky antics alongside downcast regret, darting chases next to chatty strolls, and grim art-house melodrama beside loosey-goosey hand-holding. It’s hard to imagine who besides Truffaut could have pulled it all off, and made every moment so compulsively watchable as to induce instant cinematic nostalgia.

“Shoot the Piano Player,” a new print of which begins a weeklong run Friday at Film Forum, is a suitable capper to the off-kilter surprises scattered through the theater’s ongoing French Crime Wave series. Barroom pianist Charlie Koller (chanteur Charles Aznavour) keeps patrons’ feet moving, but as a human being stays stock still, hiding out from life even before his brother Chico (Albert Rémy) enters, pursued by gangsters.

What becomes of Charlie, and what became of Edouard Saroyan, his original identity, drives the movie through its fits and starts. We first encounter the diminutive, withdrawn fellow prepping for a night’s work at the bar, which he will interrupt to help Chico give two thugs the slip. Afterward, he walks with a waitress named Léna (Marie Dubois) before retiring alone to a small apartment where he looks after his younger brother and accepts a freebie from his neighbor, the work-at-home prostitute Clarisse (Michèle Mercier).

Later on, a flashback raises the curtain on an earlier life at center stage, when Charlie was a high-paid concert pianist rather than a mere background player, with faithful but fading wife Thérèse (Nicole Berger) by his side.

Preceding the three women who pass through Charlie’s life is the movie’s quixotic opening, an unusual sidestep that functions as an ironic overture: a one-off conversation between Chico, out of breath from outrunning pursuers, and a Samaritan stranger who offhandedly explains how he married his wife before growing to love her. Charlie grows to love Léna as the two become entangled with Chico’s gangsters, Momo (Claude Mansard) and Ernest (Daniel Boulanger). In voice-over, though, Charlie expresses his well-honed impulse to retreat.

“Shoot the Piano Player” is as cine-mad and compressed in its way as Jean-Luc Godard’s contemporary call to arms, “Breathless,” though more traditionally grounded in Mr. Aznavour’s character. That chase-stroll opening is pure New Wave in its switch-up: First we’re plunged into the danger — tire squeals, floating headlights, some guy hurtling down a sidewalk, all in the natural-night darkness of Raoul Coutard’s photography (put to similar effect in “Breathless”). Then that chatty stranger comes to Chico’s aid and an impromptu, effortlessly light man-to-man chat comes together with an easygoing tracking shot that clears away the jittery cuts that had come before.

Truffaut threw everything into his second film that didn’t fit into the overtly autobiographical “The 400 Blows,” and in effect he put himself out there all the more. Certainly, his future films are noticeable in the recipe — the succession of women, the beleaguered charismatic hero — and Truffaut’s post-Cannes comedown that followed “Blows” plays out in the artistic withdrawal of Charlie’s character.

“What you did yesterday stays with you today,” says Thérèse, Charlie’s ex-wife, of better days. A glance at Mr. Aznavour’s marvelously expressive hangdog face suggests that a lot has stayed with Charlie, and by the film’s end, yet more yesterdays have been added. But the endlessly fresh filmmaking leaves no regrets for viewers.

Through September 11 (209 W. Houston St., between Sixth Avenue and Varick Street, 212-727-8110).