The Jungle Book (1967)
The Scene: Baloo knows how to take things easy in life - knowledge that he decides to pass on to man-cub Mowgli.
The Song: Throughout 'Bare Necessities', Baloo shows us exactly how it's done. The ditty's so catchy we sort of want to just slack off now and go lie under a tree.
Join In When: Mowgli has a pop at the song, too.
Little Voice (1998)
The Scene: Despite her shyness, LV (Jane Horrocks) gets up on stage for the first time ever to perform her act...
The Song: LV transforms into Shirley Bassey (at least vocally) to sing 'Big Spender' before becoming Marilyn Monroe and a whole variety of other musical divas.
Join In When: LV sings 'I Want To Be Loved By You', but only because it's fun to do the impression.
Mary Poppins (1964)
The Scene: In order to convince the kids to clean up their room, uber-nanny Mary Poppins (Julie Andrews) turns to music. And a little bit of magic.
The Song: 'Spoonful Of Sugar' is so joyful it'll get anybody cleaning - it certainly works on the kids, who can't clear up their mess fast enough.
Join In When: It all starts to spiral out of control.
Empire Records (1995)
The Scene: Before she started resembling an Egyptian pharaoh, Rene Zelleweger took to the stage as Gina to sing 'Sugarhigh' and attempt to save Empire Records.
The Song: Gina looks nervous, but when she sees people thrashing around (we assume that's '90s dancing, there), she quickly relaxes into the tune.
Join In When: The guitar solo blazes up - you don't need to know the words, just grab an air guitar and ROCK.
Hocus Pocus (1993)
The Scene: Winnie (Bette Midler) and her witchy sisters gatecrash a Halloween party, then proceed to enchant all the adults so that they "dance until they die".
The Song: A witchy version of 'I Put A Spell On You' with awesome backing-singer dance moves.
Join In When: Winnie warbles, "If you don't believe, better get superstitious" before launching into a magic spell. Scary.
Dreamgirls (2006)
The Scene: The film as a whole blows, but Jennifer Hudson absolutely kills this scene, in which she unleashes her rage on stage.
The Song: 'I'm Not Going', the film's thrilling centrepiece and an emotional zinger that can't fail to induce goosebumps.
Join In When: The big moment comes. "And... I… Am… Telllllllling you…"
Adventures In Babysitting (1987)
The Scene: Albert Collins refuses to let babysitter Chris Parker (Elisabeth Shue) and her young charges leave the stage without "singing the blues".
The Song: The result? Chris and the kids sing 'The Babysitter Blues', which is catchier than it really should be.
Join In When: Collins and his band take up the tune, ratcheting the soulfulness up to deadly levels.
Hairspray (2007)
The Scene: "The neighbours haven't seen me since I was a size 10," frets Edna Turnblad (John Travolta), before being dragged out shopping by daughter Tracy (Nikki Blonsky).
The Song: As the duo whirl through the streets, Tracy sings 'Welcome To The Sixties'.
Join In When: Edna gets in on the singing action. "Hey Tracy, hey baby look at me! I'm the cutest chickie that you ever did see!"
Sister Act (1992)
The Scene: It seems that Sister Mary Clarence aka lounge singer Doloris (Whoopi Goldberg) has performed a miracle when she turns the church choir into something amazing.
The Song: The nuns all harmonise for 'Ave Maria' to the delight of the Reverend Mother (Maggie Smith).
Jo in In When: The nuns break away from tradition for an upbeat lounge version of the song.
Scott Pilgrim Vs The World (2010)
The Scene: Scott Pilgrim (Michael Cera) has his own Jessica Rabbit moment when his ex-girlfriend's band, Clash At Demonhead, play a gig he's attending.
The Song: Envy Adams (Brie Larson) sings 'Black Sheep', sending Scott into an emotional meltdown while Ramona Flowers watches on.
Join In When: Envy sings: "Send you my love on a wire." Mostly sing along because Scott looks really upset and it’s sort of funny.