As I browsed past the Grammy Awards last night, I was reminded again how much contemporary music is about extravaganza, not musical artistry. I’m not just talking about the Spinal Tap-like egg that Lady Gaga emerged from, but all of the giant props, blazing fires, and more dancers than the audition sequence of “A Chorus Line.” It seems that the song, the actual music and lyrics, haven’t just taken a back seat — they’ve been pushed into the trunk.

That thought was reinforced as I watched the DVD of “Last Play At Shea,” a documentary about Billy Joel’s concert at Shea Stadium in 2008, the last event there before the ballpark was demolished to make way for the new CitiField. While Joel has always been a good showman, his concerts don’t include explosions and gyrations — they are about the man, his words, his music, and his connection to his fans. Most of the time, it’s Billy at his piano, backed by a pretty tight band (including the remarkable multi-instrumentalist Crystal Taliefero), singing the songs that made him famous.

But this is more than a concert film (for that, you’ll have to wait for “Live At Shea Stadium” to air on PBS in March). It’s also a history lesson. Director Paul Crowder tells the story of the ballpark, from Robert Moses’ idea of opening up the New York suburbs to the Mets going from baseball’s laughingstock to World Series champions in less than a decade to Bill Buckner’s Big Error and on and on. Tom Seaver, Mike Piazza, and Darryl Strawberry share stories, but for some reason, Crowder glosses over the fact that Shea Stadium was also home to the New York Jets for 20 years, but he does not ignore the fact that the place was a dump (Strawberry says, “Yes, but it was our dump”).

Crowder also traces Joel’s own life from Levittown to his early bands The Hassles and Attila to his success on the stages of the world, with financial betrayals and other obstacles along the way. There are interviews with all three of his wives, close compatriots, record company executives, and many others (though not a word from villains Artie Ripp and Frank Weber).

In “Last Play At Shea,” you see Joel delighting in the sea of fans on their feet and the guests who joined him that night, including Tony Bennett helping out on “New York State of Mind,” Roger Daltrey doing “My Generation,” and a guitar solo from John Mayer. John Mellencamp, Steven Tyler, and Garth Brooks were there, too, but their performances are not in the film.

Last Play At Shea” closes appropriately with Paul McCartney, a nice bookend to the history of Shea Stadium, since he and the Beatles did the first-ever rock concert there in 1965, an historic event that also was devoid of extraneous nonsense. Just four guys playing and singing to a stadium full of crazed fans.

That’s what rock and roll should always be.