Music fans looking to temper their nostalgia for classic rock ’n’ roll with some self-aware chuckles and a few hearty laughs may want to catch “Spinal Tap II: The End Continues” this weekend. A sequel to the classic 1984 mockumentary “This Is Spinal Tap,” the new movie once again purports to be a documentary of the band Spinal Tap, a group of British musicians played by Christopher Guest, Michael McKean, and Harry Shearer. This time around, “documentarian” Martin Di Bergi shadows the three band members as they prepare for a reunion concert at New Orleans, and in its minor-key-but-still-rocking manner, the comedy makes for a charming spoof of nostalgia acts and the modern-day music industry.

As before, Di Bergi is played by the actual director of the movie, Rob Reiner, who also helmed classics like “When Harry Met Sally…” and “The Princess Bride.” His affable presence, along with his trusty “USS Ooral Sea” cap, helps ease us back into the pun-heavy, relaxed humor of “This Is Spinal Tap.” He informs us that the central band members — Nigel (Mr. Guest), David (Mr. McKean), and Derek (Mr. Shearer) — haven’t spoken to each other in 15 years, and early scenes catch us up on what each has been doing, such as how Nigel now runs a cheese and guitar shop. The occasional cheesiness of the jokes is just one of the welcome traits of the viewing experience.

New characters are introduced as well, such as Hope Faith (Kerry Godliman), daughter of the band’s deceased original manager, Ian, who organizes the reunion concert after discovering a still-pending contract in his will. British comedian Chris Addison shows up as promoter Simon Howler, a character obviously parodying music impresario Simon Fuller and a judge on “American Idol” and “America’s Got Talent,” Simon Cowell. 

Quick glimpses at a couple of familiar supporting characters from the first movie, such as David’s former girlfriend Jeanine, lead to appearances by a trio of famous drummers: Questlove, Chad Smith (of the Red Hot Chili Peppers), and Metallica’s Lars Ulrich. They’re each asked to join the band, as it’s lost yet another drummer — this time due to a sneezing fit — but all of them wisely decline. Later, during an audition, the band is impressed with a young woman’s skills and quickly hires her. Actress Valerie Franco is not only a drummer in real life but a refreshing presence. 

That her character, Didi, is youthful and female goes a long way to helping mitigate the misogynistic and even somewhat pedophilic tenor of some of the band’s songs, however humorous the lyrics may be. The movie’s writers, including Mr. Reiner and the often improvising lead actors, vaguely acknowledge how social mores have changed since 1984, though Fran Drescher’s character in the earlier film also noted the band’s sexism. The clueless crassness of three bandmates may be why they strike viewers as more endearing than harmful.

One gets a sense of the three actors’ deep love and respect for music through the many rehearsal scenes and from two key guest stars: Paul McCartney and Elton John. Indeed, the mockumentary almost seems like a sincere rock doc at times due to its multiple performances, references to music history, and focus on details like guitar pedals. These devices are featured in a couple of comic bits, including one near the end that prompts a very funny line, yet they never feel as memorable as when Nigel pointed out how his amplifiers went up to 11 in the first movie.     

After a segment in which Sir Paul attempts to give David a note about a song the band is rehearsing, the rock and roll legend joins them for a lovely version of “Cups and Cakes.” The ditty is a droll paean to the English teatime tradition and reflects how the band’s songwriting extends beyond metal or prog rock songs. Sir Elton turns up later in the film, including during the reunion concert climax, and the bespectacled icon, who loves a good joke, also comes off as a good sport.    

A few jabs at the commercialism of the industry land mirthfully, though the reliance on Mr. Addison’s slimy character grates after a few scenes. In general, gags of wry amusement outnumber those that inspire laugh-out-loud moments. Still, all three lead actors are as terrifically deadpan as ever, and each shines in individual scenes as well as group skits. 

Throughout the film, there’s a tension regarding what caused the rupture between David and Nigel many years ago, but once this secret is revealed, and it amounts to a rock and roll cliché, it’s just as quickly forgotten. It’s a wise choice, as one doesn’t watch “Spinal Tap II” for drama or insight. “Why waste good music on a brain?” a character asks, and the movie’s knowing tone and uproarious, tragicomic ending both belie and bolster the question.