If you're reading this column, you probably either know him or you are him.

Whom are we talking about? The guy in the movies - and in real life - whose most important relationship is not with another human being, but with the music he loves with consuming passion.

He comes in all shapes and sizes, most of which are not quite as attractive as the piano-playing hunk Ryan Gosling plays in director Damien Chazelle's musical valentine to Los Angeles, La La Land. (And, with a few exceptions, like Kristen Stewart as Joan Jett bouncing around her bedroom writing "I Love Rock 'n Roll" in 2010's The Runaways, it's almost always a he.)

Sometimes he's a collector, like Steve Buscemi accumulating jazz and blues 78s in Terry Zwigoff's 2002 adaptation of Daniel Clowes' comic Ghost World. Or John Cusack's less emotionally handicapped record shop owner in Stephen Frears' 2000 take on Nick Hornby's novel High Fidelity.

Generally, these guys are good at driving women away, with no one better at it than Shrevie, Daniel Stern's character in Barry Levinson's 1982 male-bonding classic Diner. When his wife, Beth, played by Ellen Barkin, incorrectly refiles a James Brown album, her hubby goes over the edge.

"It's just music," she says. "It's not that big a deal." What? Just music! Not that big a deal? The collective male music-geek stereotype recoils in horror. "This is important to me," Shrevie mansplains. "Every one of my records means something! When I listen to my records, they take me back to certain points in my life."

Nostalgia for a bygone era - an all-but-inescapable syndrome for music obsessives - runs throughout La La Land, a dazzling dreamscape of a movie unabashed in its evocation of the Golden Age of the Hollywood musical. But the charming Gosling and Emma Stone romance doesn't only wear its heart on its sleeve for vintage Tinseltown productions like the Fred Astaire and Ginger Rogers vehicle Swing Time (which, by the way, is an inspiration for British writer Zadie Smith's ambitious new novel named after the 1936 musical).

La La Land is also all about jazz. Specifically, it's about the Gosling character, Sebastian, and his uncompromising devotion to the music and his dedication to a sketchily defined concept he calls "pure jazz."

In film, a collaboration among writer-director Chazelle, composer Justin Hurwitz, and lyricists Justin Paul and Philadelphia native and Friends' Central grad Benj Pasek, we witness that dedication in the opening number, "Another Day of Sun." While others use the occasion of a freeway traffic jam to leap about and burst into song as cast members in musicals do, Sebastian stays in his car, listening to a piano composition he's working on. All work and no play makes Sebastian a dull boy, but one with vaulting ambitions.

His insistence on thinking about jazz as art rather than mere entertainment is akin to the attitude of the title character Oscar Isaac plays in Inside Llewyn Davis, the Coen brothers' 2013 evocation of 1960s Greenwich Village. In that depressive comedy (which improves the second time around), sad sack Llewyn, like Sebastian, is a talented artist who considers mere pop beneath him. "I'm not a trained monkey," he says when asked to entertain at a dinner party thrown by patrons he's happy to sponge off of.

In La La Land, Sebastian's self-seriousness is more charming. The friendless musician is visited by his sister and refuses to let her sit on his precious piano stool, once owned by 1930s Tin Pan Alley songwriting great Hoagy Carmichael. She mocks how he clings to the starving-artist stereotype. He replies: "You say romantic like it's a bad word!"

La La Land is about the necessity of suffering for your art. That also goes for Stone's aspiring actress, Mia, who toils as a barista before running off to endure one humiliating audition after another, sometimes with hot coffee spilled on her blouse.

And Sebastian's suffering includes debasing himself by playing poolside in an '80s cover band, and later putting his ideals aside by joining a pop band fronted by a character played by John Legend in a plot contrivance I didn't buy for a second. (It's a smart career move for Penn grad Legend, though, who plays guitar rather than piano and is a voice of practicality in the face of Sebastian's conservatism: "You're holding on to the past, but jazz is about the future.")

The movie makes plain the idea that nothing should be expected to come easily to "the fools who dream, crazy as they may seem," as Mia sings in "Audition (The Fools Who Dream)," the strongest song (which Hurwitz analyzes in the current episode of Hrishikesh Hirway's Song Exploder podcast). But La La Land is a leisurely saunter in the park compared to Chazelle's previous feature, 2014's Whiplash.

That movie won a best supporting actor Oscar for J.K. Simmons as a sadistic conservatory instructor, and its male protagonist was also a jazzman, in this case (like Chazelle himself) a drummer. Starring Miles Teller as the ambitious player willing to beat his kit till his fingers bleed, it's a dynamic film that's much harder to watch than La La Land, though it explores many of the same themes.

Whiplash ranks jazz as the most exacting of art forms - a poster in the hero's practice room bears the headline: "If you don't have the ability, you end up playing in a rock band." Like Sebastian (until he meets Mia for the third time and finds her irresistible), Teller's Whiplash character doesn't have time for a relationship. He cruelly dismisses his girlfriend because she'll only take up time he needs to spend practicing.

And Simmons - who also has a small role in La La Land - boils the "fools-who-dream" concept down to the blunt essence of what Chazelle's movies are about: "To push people beyond what's expected of them - I believe that's absolutely essential."

To make that happen, is there room for another person in the picture? In Whiplash, there isn't. The pursuit needs to be single-minded.

La La Land, by contrast, works in the idiom of the pixie-dust-sprinkled Hollywood musical. It's a love story that tests the happy-ending machine to see whether not only our highly principled musician, but also his equally ambitious and hardworking actress paramour can achieve their goals, together. Are these crazy dreamers going to make it? No spoilers here.

215-854-5628@delucadan