Ravel's "Boléro" is indeed one of the most referenced pieces in the modern music canon. Composed and performed during the period in which this Babylon film is set!
Who doesn't want to see Brad Pitt as Cliff Booth in every movie he's in from now until the end of time? Looks like a big hit. The young Antonio Banderas guy will probably become a big star. Damien does Baz! Hooray. I love Cliff Booth.
There're a couple classical music references throughout the score. The reason is because it's common practice in silent era to use existing classical music as score and this film is about the transition from silent to sound. "Gold Coast Sunset" is clearly inspired by Liebestod from Tristan and Isolde; "Morning" is obviously based on Schubert's Piano Trio No. 2; "Night on Bald Mountain" is, well, Night on Bald Mountain, and Mussorgsky even got credited; the Bolero riff is another example.
On a side note, "Champagne" looks like is based on an unused idea for "Another Day of Sun" in La La Land. Check this video around 14:30 when Hurwitz talks about melody that didn't work https://youtu.be/8id8dqQVpKY
Listening to it now. Maybe I'm in the minority, but this music seems a little...obnoxious. The blaring brass would've been fine in a couple tracks, but it's smeared over half the 97(Holy Christ!)-minute album. Every once in a while, the music calms down and offers something good ("New York", "Gold Coast Rhythm"), but those bits are few and far between.
Also, I'm as far from a prude as you could imagine, but that one song (I'm sure you can figure it out)...yikes.
The reviews for this film are rather mixed that it's put me off seeing it, but the music tracks that have been posted are absolutely superb ! What a fantastic composer Justin Hurwitz is !