Meryl Streep can do no wrong. She is absolute perfection in everything she does, and having worked in cinemas and as a film reviewer across 32 years now, I must have said that line myself a few dozen times.

Singing Meryl Streep aside, I wasn't thrilled at the prospect of sitting down to a more-than-two-hour musical. I loved musicals as a kid but whatever middling interest in them retained over the years was fairly killed off by Tom Hooper's woeful Cats feature film version last summer.

The fact that The Prom also cast James Corden didn't inspire much hope either, but I'm surprised to report that my misgivings were misplaced and that Ryan Murphy has produced quite a lovely and extremely colourful musical feature.

The Prom began its life as a stage production, first in Atlanta and then enjoying a year on Broadway at the Longacre across 2018-19. It featured a slew of musical numbers by the team of composer Matthew Sklar and lyricist Chad Beguelin, whose stage adaptations of The Wedding Singer and Elf were big hits.

If anyone were to adapt The Prom for the big screen, Ryan Murphy was the most sensible choice. He made television musical fashionable again with his singing series Glee and he has peppered his innate camp sensibility across everything he does.

At the centre of The Prom is the story of high schooler Emma (Jo Ellen Pellman) from rural Indiana, whose request to bring a girl to the school prom creates quite a stir. She and her crush Alyssa (Ariana Debose) are denied by the school despite the sympathy of principal (Keegan-Michael Key).

Their story makes its way to the ears of Broadway performers Dee Dee Allen (Streep) and Barry Glickman (Corden), a couple of hams whose splashy new show about the lives of Eleanor and Franklin D. Roosevelt has bombed, giving them urgent need for a bit of PR rehabilitation.

Deciding to take on Emma and Alyssa's cause, and with Broadway pals Angie (Nicole Kidman) and Trent (Andrew Rannells) in tow, the fading Broadway stars attempt to insert a little show-business in the kids' fight with their school.

The best things about this film are the two least flashy roles, the young couple. Jo Ellen Pellman is introduced as a clear-voiced charmer with the song "Note to Self". "Note to self, don't be gay in Indianna", it begins, and we see the casual and not-so-casual discrimination she faces daily.

Later, Adriana Debose displays the big voice in Alyssa Greene that we're likely to become a lot more familiar with when Stephen Spielberg's West Side Story is released next year - she is his Anita. On her arrival in town, Meryl's character Dee Dee belts out the delightfully wry "It's Not About Me". Hilarious self-aware stuff.

The numbers are all pretty good, not a dull one among them. Andrew Rannells, whose voice I came to love on repeat listenings of the Book of Mormon Broadway soundtrack, has some of the best lines in "The Acceptance Song". "Bigotry's not big of me, and it's not big of you," he croons.

Our Nic leans in to her breathless Monroe in the fun number "Zazz", and even James Cordon is in fine voice with the slow number "Simply Love". From the big names, the performances are all over the top, but when you're playing washed-up hams, they're suitably so.