In Sex&Drugs&Rock&Roll Denis Leary plays a washed up rocker who is given one last chance to hit the big time. The show, which debuts July 16 on FX, shows another side of Leary’s storied Irish American upbringing. If rock bands are indeed the big, dysfunctional families that the show says they are, he’s had a lifelong training for the role.

Quick, how long has it been since you saw a punk rocker under 30? Now, we’re talking Mohawk hairdo and safety pins through the nose and “Anarchy in the U.K.” t-shirts here.

It’s been a long time, hasn’t it? The truth is punk went the way of all flesh years ago, so when you actually see one nowadays you’re likely to have the same reaction as when you see someone dressed for a Renaissance Fair. What century do they think it is granddad, you’ll likely wonder?

Irish American Denis Leary is well aware that the mighty rock fantasies of his generation have passed. But his new show on FX, Sex&Drugs&Rock&Roll, asks if you can ever really put a best-before date on dreams?

Leary, 57, plays Johnny Rock, lead singer of a band called the Heathens. He’s a sort of man-child throwback to a 1980s rock era that has long since vanished. But Johnny still can’t let it go, nor can he quite believe he’ll never be the star he felt certain he would be.

In the years that followed Johnny’s former band mate Flash (John Corbett, best known as Carrie Bradshaw’s boyfriend Aidan in Sex and the City) has actually done the things that Johnny is still dreaming of. He plays in Lady Gaga’s band, he’s a big success, and he’s long since moved on from the gigging days that are still Johnny’s lot.

Into this mix comes Johnny’s 25-year-old love child Gigi (Elizabeth Gilles), the product of a one night stand who is now lead singer of The Assassins. Gigi has the youth, tunes and stage presence of a major rock star, but she can’t write a song to save her life.

Gigi’s plan is to talk Johnny and Flash back into working together again to write her a few hits, a task she fondly imagines won’t be very difficult. For his part Johnny sees her as a last chance to rescue his own falling star.

If all this sounds like a million miles from Leary’s last hit Rescue Me, which was set in the heavily Irish American world of firefighting, think again. (The star, whose parents were both born in Killarney, Co. Kerry, told US Weekly last weekend that his dad “was a brilliant auto mechanic who sometimes had a short temper. I do not know how to fix an engine, but I can curse a blue streak in Gaelic.”)

When Leary first stepped out on the American stage he was known for a kind of punk rock snarl, giving voice to edgy material that got him noticed immediately. That awareness has shaped his new show.

“My experience was, every band I've known -- famous and not famous -- have a family dynamic,” Leary told the press at Comic Con in San Diego last weekend. (Leary is also the writer and executive producer of Sex&Drugs&Rock&Roll).

“I come from a big Irish family. I’m used to bitterness, resentment, grudges and screaming at each other. That's normal to me, so I thought, if we’re looking at a family, we need that level of feeling and emotion.”

Leary has played guitar since high school and has known rock and rollers who went on to hit the big time since his undergraduate days at Emerson College in Boston. But they weren’t the ones that interested him most, he reveals.

“I was much more interested in the guys that should have been famous. There were a lot of great bands in New York and Boston at that time who failed, and I thought those guys were really interesting,” he told the Daily News.

What reunites old bands faster than the lure of cold hard cash? Even bands where the members have visibly fallen out have been coaxed back onto the stage by the thought of a few million in the bank. So it proves with Johnny Rock and his old compadres in Sex&Drugs&Rock&Roll

Gigi, for reasons that are not explained in the first four episodes, has arrived in New York with a serious chunk of change in her bank account, which means she has the wherewithal to lure her dad’s estranged band members back into the studio to write her hits.

Still as argumentative now as they were then, lead guitarist Flash (Corbett), bassist Rehab (John Ales) and drummer Bam Bam (Bobby Kelly) are still the combustible mix they always were, but Johnny has changed in one very significant way. He knows it’s his last shot and he wants it to work this time.

There’s as much room for tragedy as comedy in Sex&Drugs&Rock&Roll, but Leary wisely keeps his focus on the absurdities of a (in real life) 57-year-old man trying to rock leather pants in 2015 as if it was 1980. Johnny also has an eye-popping Joan Jett (she actually appears in the show in a cameo) meets David Bowie meets Linda McCartney spiky hairstyle that is, there’s no question, one of the funniest aspects of the show.

The backstage bickering playfully echoes Spinal Tap, some classic rockumentaries and lower grade school. There aren’t many bands who are so dysfunctional that they break up on the same day their debut album is released, and that’s the kind of absurdity that powers the show.

The Irish note is in the inability of anyone in the Heathens to acknowledge the strength and contributions of the other three. Prodigiously talented, but unable to keep their own riotous feelings in check long enough to triumph, they somehow manage to snatch defeat from the jaws of victory, which explains Leary’s fascination with the characters and why they resonate for him.

The specter of David Bowie is all over the show, and Leary has made no secret of his desire to have him appear. “I grew up in the ‘70s when there was s***ty music,” he said at Comic Con.

“The songwriters and the musicians were falling asleep, and there were stupid haircuts. Bowie got me through the 1970s until the Ramones showed up. He’s funny; I’ve seen him on Ricky Gervais' show. That’s my message to David Bowie.”

But at 57, Leary looks more like Aerosmith’s famously wrinkled Steven Tyler than the Thin White Duke. His dad rock ambitions embarrass Gigi, who thinks his time has passed and he should face it. Johnny has no intention of listening to her, though.

And looking back at what you did wrong is harder when you’re still dressed like what you did wrong. Johnny’s biggest problem is that all the elements that made him unstable then, like selfishness, self-importance and an inability to see anyone’s point of view, are still largely present now, making the question of whether the Heathens can rise again an open one.

Can Johnny quit drugs and booze to sober himself up enough for his last big shot at fame? Can he keep his mouth shut long enough not to alienate everyone around him like he used to? Can he hell.

When one of the Heathens tells Johnny he has written a 29-part song cycle about the Irish potato famine, Johnny replies, “You’re Jewish – shouldn’t you be writing about the Holocaust?”

“The Holocaust,” his band mate says, turning up his nose at the suggestion. “It’s got such a History Channel vibe now.” That’s the sort of crack that lets you know the Heathens are in for a bumpy ride.

Sex&Drugs&Rock&Roll debuted on Thursday, July 16 on FX at 10 p.m.

Denis Leary as Johnny Rock in Sex&Drugs&Rock&Roll.