What’s the difference between Bill Murray and Al Pacino these days? Not much. Pacino might be shorter, Murray might have less hair, but otherwise they could be spiritual brothers from alternate cinema universes — seriously. Someday, a producer will stumble upon that truth and make a buddy movie with the two of them. In the meantime there’s “Danny Collins” starring Pacino, which opens in Japan the same week as “St. Vincent” with Bill Murray.

They’re both delightful films, affording the same sort of dry, bitter flavor redolent of old sherry. Pacino and Murray can be major assholes, but that’s part of their charm. They’re the kind of guys older women dream of dating, mainly because they seem open to the idea of dating older women. Besides, few men can get over the hill and still know how to spew one-liners with attitude and a wink. If you’re in the mood for pointers on life after 60, Murray’s Vincent is the go-to guy, but for soul-searching after 70 — with John Lennon’s greatest hits playing in the background — Pacino’s Danny is your man.

Having just piled on the compliments, it’s a tad regretful to have to say that “Danny Collins” isn’t one of Pacino’s best works. And that’s putting it kindly. Danny is rich and obnoxious, an aging rock star schmuck who lives in the Hilton and hangs out with Annette Bening. He has no idea of the struggles of the 99 percent, the plight of fast food workers or the devastating effects of climate change. (At least Vincent was aware of the problems of modern life and was depressed about them.)

Danny has lived the past four decades in a haze of money, drugs and a succession of young, hot babes to share his overprivileged existence with, thanks to a platinum album he sold back in the 1970s and an enduring fan base consisting of mainly of old women. He doesn’t even have the decency to get twinges of existential angst.

One day Danny’s agent and best friend, Frank (Christopher Plummer), finds a letter written by John Lennon, recovered from a private collection. It turns out Lennon (whom Danny idolized back in the day) had listened to Danny’s music in 1971 and taken the trouble to offer words of wisdom to the young musician about how fame and fortune can’t corrupt an artist’s work, they can only corrupt themselves.

“Danny Collins” is loosely based on real-life events, and director Dan Fogelman drills into that mine like a fracker hell-bent on short-term profit. Almost instantly, Danny goes from remorseless old man with a ridiculous wardrobe to a mature human being who wants to make amends — with himself, his music and an estranged 40-year-old son named Tom (Bobby Cannavale). It’s a convenient change of heart, but there’s no chance to dwell on the details, the story on at breakneck speed — “I can’t waste any more time,” says Danny.

He moves into the Hilton in New Jersey (right in Tom’s neighborhood) and sets about flirting with classy hotel receptionist Mary Sinclair (Bening) by day while trying earnestly to rekindle his musical flame by night. Danny even installs a grand piano in his room, though the man hasn’t written a song in ages.

The family thing is a more difficult. Tom seethes with contempt for a father who neglected him for so long.

A blue-collar worker with a saintly wife (Jennifer Garner) and a small daughter, Tom pointedly tells his father that he has spent his whole life “trying not to be like you.” Ouch. “Danny Collins” would have benefited from more of the gritty father-son conflict, but Tom capitulates all too soon and Dad is let off the hook without having paid his familial dues.

The takeaway lesson is that after you reach a certain age, it’s not about money and status but the will and ability to charm.