So, now that watching this movie is one of the things I've done with my life, I should probably try to wring something out of it.
1) Rhinestone takes fake audiences to the next level. If I had to pick a winner between the pantomime clap-along in the first musical scene (where they were clearly instructed not to actually let their hands collide in a way that would produce sound), and the surreal fake laughter of the same audience later on (where I have no idea what they were told), I would choose to nail the doors of the venue shut, and set it on fire. From the inside. So I could forget, forever.
2) Richard Farnsworth pretending to sing and play guitar is worth the effort of getting this movie, if you happen to hate good things. The awkward aside conversation to Stallone's character -- during a song -- features Farnsworth bobbing up and down in such a disturbing, unwholesome fashion that it made me think of his scene in The Straight Story where he's sitting around a campfire with a teenage hitchhiker girl he had passed on the road, talking about family and holding a weiner in his fist.
3) I keep thinking about Gold Eagle Murder Singer (whose song is clearly an attempt at an alibi for his Loretta's allegedly accidental death-by-tractor). Freddie Ugo is certain he will kill the crowd (figuratively), because, as he says, "I coached him myself". Assuming that's not just bluster, I wish we could have seen that movie. I'd love to learn how Ugo, who seems to never have an unexpressed thought or an unfiltered emotion, bossed Gold Eagle around and somehow didn't end up accidentally killed by his own limousine.
4) I insist that the first song Nick and Jake perform together, in the Tennessee bar before returning to New York, actually works. Not works-works, but at least movie-works. He still can't sing well, but he sings well enough that it's not fully comical, and for the last couple of minutes their stage chemistry clicks well enough that -- in the movie world, at any rate -- you could believe they were going to go on and win the day. But it's as though the filmmakers only had a certain amount of competence to spend, and they sunk it all into that sequence, because once they hit the stage in New York, it's just poop. Poop, poop, poop. I'd really be interested to know whether they shot that segment first, or maybe last, or if there was some other production factor that caused it to come within range of what they were aiming for when everything else went so far off the mark.
5) Stallone seems to have an intermittently effective comedic deadpan. As long as he's not speaking or doing things, and is just reacting facially to something in his environment, his performance has unironic positive value.
6a) Let us announce quorum on this point: "You sound like baby Hitler" is one of the best lines in cinematic history.
6b) And also this point: Dolly's voice is so good it's almost unreal. If I heard a new singer today doing what she can do, I would write it off as studio gimcrackery.
7) Mike Post was involved with the score, but Sylvester Stallone wrote or co-wrote five of the songs. Obviously I can't help but wonder how it would have turned out if Post had written those songs instead of Stallone, and had punched up the script instead of Stallone, and had starred in the movie instead of Stallone.
It's a sunny day, maybe I should go outside now.