By JAY WEISSBERG
After the multicharacter juggling in “Bits and Pieces,” Antonello Grimaldi discovers that a stripped-down cast suits him just fine in “Quiet Chaos.” Tale of a recent widower learning to integrate grief into life as a single parent will inevitably be compared to “The Son’s Room,” not least thanks to Nanni Moretti’s presence here as lead, but the current offering is a gentler, deceptively simple drama looking at life as much as death. Beautifully modulated, fluidly told film expresses pain with warm understatement, and while sales may be slower than for Moretti’s own work, arthouse auds should feel a gratified satisfaction.

The screenplay co-authored by Moretti -- and the Sandro Veronesi novel it’s based on -- are welcome reminders of a thoughtful yet emotional maturity existing in Italo literature all too often absent from movie screens. Film exec Pietro (Moretti) has an eventful morning at the beach with brother Carlo (Alessandro Gassman) when he rushes into the water to save a woman, Eleonora (Isabella Ferrari), from drowning. On returning to his summer home, he finds his wife Lara has been killed in a freak falling accident.

Back in Rome, Pietro discovers all the small, necessary steps required of a now-single parent to bring up 10-year-old daughter Claudia (Blu Yoshimi). When classes begin again, he takes her to school and, in a spur-of-the-moment thought, decides to wait in the park across the street until she comes out again. So begins Pietro’s new routine: He drops Claudia off, reads the newspaper and slyly exchanges glances with nubile dog-walker Jolanda (Kasia Smutniak).

Pietro’s need to be near Claudia at all times isn’t expressed in words, just deeds, and the routine he develops in the park becomes not just a substitute for his regulated office life, but a discovery of his true feelings -- which, like proper emotions, are not always resolved. The introduction of a Down syndrome boy with whom Pietro interacts at first hits a dissonantly sweet note, but Grimaldi masters it, using it to turn Pietro into a person more aware of himself and others.

There’s an element of suspended disbelief here, as film executives (Roman Polanski has a cameo as a major industry player) turn up in the park to meet with the outwardly calm Pietro. His suffering isn’t in question, but the chaos of the title is never the turbulent maelstrom everyone, including Pietro himself, expects.

Moretti’s performance is refreshingly understated, even warm, yet his eyes reflect a palpable sense of emptiness until the moment he comes to terms with his loss. Other roles are equally well cast though ultimately minor, from Valeria Golino’s animalistic breeziness as Pietro’s sister-in-law to Gassman’s sexy-while-sympathetic uncle routine. Dialogue flows easily, and Grimaldi interpolates the right amount of humor.

Lensing is crisp and unself-conscious, Angelo Nicolini’s editing beautifully restrained. Grimaldi displays his most sophisticated feel for music yet, organically inserting songs by Rufus Wainwright, Radiohead and Ivano Fossati to highlight emotion. Especially memorable is a sequence with Pietro waiting by a bench as scores of parents arrive in groups to pick up their children from school. His loneliness stands out, but so, too, does a sense of commonality.