Sure it is.
If you claim that it’s not because all the songs (except for “Can’t Buy Me Love”) are performed by professional musical performers in the context of a musical performance, instead of Regular Joes breaking out into songs and dances, I give you CABARET. You’re saying THAT’S not a musical?
Not merely that, but the songs are not used to advance the plot. Sure, the presence of songs of some sort is integral, but they could be ANY songs; they are, lyrically, not used to reveal motivations or as an extension of the dialogue. This is what separates the “musicals” before Showboat, in which the songs were a jarring tack-on, from those after, where the songs become part of the story and why the operetta question becomes important.
I can’t claim that this is much of a film for music, but egads, what a fun movie. The romantic lead is a plumber named Mr. Zabladowsky. The kid makes an atomic bomb. They slip in an in-joke about Kim Czerny. And the sets…forget the Grinch; this is the closest you’re going to get to Dr. Seuss in a live action film.
Other musicals near and dear to my heart:
Singin’ in the Rain: It’s like a bad drug – if I channel surf past it on TV, I must stop and watch it. “I caaaaaahn’t stannum…”
Bugsy Malone: Okay, not really. A clever film featuring a young Scott Baio and Jodie Foster, but Paul Williams’s music is pretty dull after a while (anyone see Phantom of the Paradise? Awful.).
Labyrinth: Another fun and surreal film.
Pirates of Penzance: How can you not like Kevin Kline being…well, Kevin Kline? Rex Smith, in the only worthwhile musical endeavor in his career? Angela Lansbury? Sweet-faced Linda Ronstadt, pre-inflation? Excellent casting, and a fun score. I’d mention Topsy Turvy here too, but it was too depressing.
South Park: BLU: Oh sweet Jesus, keep me away from this film or I’ll have the song “Unclef**kers” stuck in my head all day…[sub]Excuse me while I go beat my head with a brick to exorcise this movie…[/sub]
Am I the only one who thinks that a great double-bill would be Dr. T and the Women and **The 5,000 Fingers of Dr. T[/]?
I saw T5KFofDrT at a summer filmfest for kids. Partway through the film, after a musical number by three portly guys dressed in Seuss-inspired livery, one of the janitors watching in the back turned to another and asked, “Can you believe people get PAID for this?”
Goddamn Wagnerites, there’s no reasoning with 'em. (insert smiley face here)
“Singin’ in the Rain” - the second musical I ever saw on the screen. sigh
“Funny Face”
“Nightmare Before Christmas”
“The Little Mermaid”
“Labyrinth”
“The Pirate Movie”
Now… does Hudson Hawk count as a musical?
[hijack]
Cal, your sig forced me to finally look up what it refers to. Wow. I could get to like Yeats.
[/hijack]
Or, for another “all-time bad” movie musical, how 'bout The Pirate Movie?
Kirsty McNichols gets hit on the head (not hard enough) and dreams that she’s in a bad, disco-ized version of The Pirates of Penzance.
To make matters even worse, as the cast is “singing” one of the few relativly un-butchered (excuse me…un “updated”) G&S songs, McNichols chirps in with a smarmy line to the effect of “Can you believe that Gilbert and Sullivan were paid to write this junk?”
Considering that G&S are fondly remembered after 120 years or so, and you were a has-been at 23, I’d say you were in no position to talk, Kristy.
Fenris
To be honest, I had no idea I cared so much about this or that there was actually a subject on which I could be fairly knowledgeable and lucid! Surprised the hell outta me; like I was possessed by the spirit of Truman Capote or something.
Ok, so let me suggest a couple of hard cases, two of which I named as among my favorite “musicals”:
Yellow Submarine: Here, the plot and characters were twisted in order to make the songs reveal motivation (e.g. “Nowhere Man”). The end result, I would argue, still meets the test of musical.
Hairspray: One could argue that the songs used could be “any” songs, but I don’t think that’s really the case. Would the final scene have been possible without using “The Roach” followed by “The Bug?” Nope. (BTW, a Broadway production is apparently in the works.)
Pulp Fiction: I think this is the hardest case. I’m hard pressed to think of a “non-musical” film that more effectively uses music as a commentary on character development - would any song have worked as well as “Girl, You’ll Be a Woman”? or “Son of a Preacher Man”? And yet it’s definitely not a musical.
And what is the “operetta question?” More importantly, what’s the answer?
Earlier on this page I asked, “What IS the difference between an operetta and a musical?” I expected Eve to pop in and give an answer we could agree on. She hasn’t, so the question remains unanswered.
For me, the MOST important question is, “Why do I care?” I can’t answer that, either.
We just watched the Sound Of Music DVD last night. My daughter, my wife, and I all love it. We’re gonna watch West Side Story tonight. If a widescreen version of Singing In The Rain ever shows up, my collection will be complete. And this from a guy whose DVDs mainly consist of R-rated body-shredding sci-fi.
Hey, the movies you mentioned have Nazis and knife fights and Donald O’Connor doing his impression of a Tex Avery cartoon. What more can a guy want?
I asked this years ago on rec.arts.theatre.musicals and got a looonng, in-depth, MEGO (my. eyes. glazed. over) explaination of music theory/tempo/time signatures/etc. The upshot of the explanation is that it’s the type of music (tempo, rhythm, something) that determines that it’s an operetta and not a musical, rather than the story, song placement, format etc.
I’d look it up, but Google has destroyed “Deja-News” and I didn’t keep the post, but that’s a whole other rant.
Fenris
The Sound of Music
I love most standard stage musicals, like R&H, The Music Man, My Fair Lady, and my all-time favorite, Guys and Dolls.
But when I think about movie musicals, the ones that spring to mind are:
Anchors Aweigh
A Star Is Born (Judy Garland version)
Easter Parade
and the one I just discovered last month, and fell completely in love with
There’s No Business Like Show Business - wonderfully sappy plot with characters I really cared about, some great Irving Berlin songs, and divine dancing by Donald O’Connor.
And I’d just like to add…
June is bustin’ out all over
The feelin’ is gettin’ so intense
That the young Virginia creepers
Have been huggin’ the bejeepers
Out of all the morning glories on the fence!
Because it’s June
June, June, June
Just because it’s JUNE, JUNE, JUNE!
Good show! 
SV, please join me in a chorus of the solo bit:
March went out like a lion
A-whippin’ up the water in the bay.
Th’n April cried and stepped aside,
And along come purty little May!
May was full o’ promises,
But she didn’t keep ‘em quick enough for some,
And a crowd of Doubtin’ Thomases
Wuz predictin’ th’t the sun’d never come.
<guys>
But it’s come, by gum!
Y’kin can feel it come,
Y’kin can feel it in yer heart,
Y’kin can see it in the ground,
<gals>
Y’kin can see it in the trees,
Y’kin can smell it in the breeze
<both>
Look around, LOOK AROUND, LOOK AROUUUUUUUUNNNNNDDDD!
Fenris (who has a very, very,VERY wrong urge to spell it “cum”…which kind of changes the meaning, doesn’t it 
)
Slight hijack here, but I wanted to ask about a movie that HAS been mentioned, Fantasia.
Has anyone here ever seen a book called “Cartoon Confidential”? It details items in cartoons that were controversial and/or later censored.
For Fantasia the books tells how one segment was doctored sometime after being originally released. There is even a still photo from the deleted scene. Remember when the girl centaurs are primping before they meet the guys? Well, originally they had an extra helper, not just the little cupids. It was a girl child centaur, who acted in a maid capacity, polishing hoofs, doing nails, etc. And this child was black, with pickaninny style pigtails sticking out all over, big lips, the whole stereotypical shmeer. I guess when Disney thought their bottomline would suffer, they got politically correct. Some comapny.
Okay, Fenris, your heterosexuality hangs in the balance. Did you know that or did you have to look it up?
Hey! I’ve seen that!