Of course, people don’t break out into song at the most emotional moments of their lives. That’s why we have musicals.

But audiences these days don’t necessarily want the classic strains of “Oklahoma!” or “My Fair Lady.” They’re after something a little more unusual and challenging.

With the musical P.T. Barnum biography “The Greatest Showman” and the a cappella-filled “Pitch Perfect 3” hitting theaters this pre-Christmas weekend, here are seven musical movies that break, or at least bend, the rules.

1. Phantom of the Paradise (1974)

A little “Phantom of the Opera” and a little “Faust,” as a record executive, Swan (Paul Williams, who also wrote the songs), sells his soul for eternal youth and riches. He steals music from a composer, Winslow Leach (William Finley), who’s disfigured in an accident and inhabits the bowels of Swan’s new rock palace, the Paradise. Leach plots revenge against Swan, but also agrees to finish the rock opera that will make a star out of a beautiful young singer, Phoenix (Jessica Harper). Directed by Brian De Palma, this rock musical is a paragon of rock ’n’ roll excess.

2. Bugsy Malone (1976)

Director Alan Parker has a lot of musicals on his résumé: “Fame,” “Pink Floyd the Wall,” “Evita” and “The Commitments.” But his first was his strangest: a gangster epic with children in all the roles, wielding Tommy guns that shoot marshmallow fluff (or “splurge”). Scott Baio plays the title character, a good-hearted gangster caught between rival factions; Jodie Foster also stars as the singing gun moll Tallulah. Once again, Paul Williams wrote the songs here.

3. Pennies From Heaven (1981)

Screenwriter Dennis Potter adapted his acclaimed British miniseries for Hollywood, a sad story of a Depression-era sheet-music salesman (Steve Martin) who fantasizes that the world can be as rosy as the songs he sells. Director Herbert Ross borrowed the miniseries’ conceit of having the stars — who include Bernadette Peters, Jessica Harper and Christopher Walken — lip-synching to old standards throughout the story. The result is surreal, bleak and extremely watchable.

4. Cry-Baby (1990)

John Waters indulges his sweet-tooth for ’50s delinquent dramas with this musical tale of a slick-haired bad boy (Johnny Depp) who wins the heart of a rich good girl (Amy Locane). Depp does his best Elvis impersonation in this campy tale, which boasts a diverse array of supporting players including Iggy Pop, Traci Lords, Ricki Lake and Troy Donahue.

5. Cannibal! The Musical (1993)

Long before “South Park” and “The Book of Mormon,” Trey Parker and Matt Stone created their first bizarre musical, telling the story of prospector and admitted cannibal Alferd Packer. Parker and Stone were just college kids at the time, but the movie (directed by Parker) is surprisingly polished. When the Sundance Film Festival rejected the movie, Parker and Stone rented out a hotel room in Park City, posted fliers around town and showed it to anyone adventurous enough to go inside.

6. Hedwig and the Angry Inch (2001)

John Cameron Mitchell’s off-Broadway extravaganza made for a colorful and profoundly moving movie about Hedwig (played by Mitchell, who wrote and directed), an East German émigré who turned his pain from maternal rejection and a botched sex-change operation into grist for her fierce punk songs. Backed by Miriam Shor (as Hedwig’s put-upon guitarist Yitzhak) and the incomparable Andrea Martin (as her stalwart manager, Phyllis Stein), Mitchell gives a tour-de-force that plumbs Hedwig’s pain, humor and resilience.

7. The Last Five Years (2014)

The beginning, middle and end of a romance, through courtship to marriage and divorce, are told in both directions — backward by the woman (Anna Kendrick), a struggling actor, and forward by the man (“Supergirl’s” Jeremy Jordan), an up-and-coming novelist. Writer-director Richard LaGravenese, adapting Jason Robert Brown’s two-hander stage play, gives his stars plenty of room to sing their hearts out — and the result may be the unheralded gem of Kendrick’s career.