Nathan Phillips’s review published on Letterboxd :
Melancholy, unabashedly nostalgic and slightly overlong musical about a couple of career-oriented artists (a passable Emma Stone and an entirely charisma-free Ryan Gosling) crossing romantic paths in Los Angeles -- and the Warner Bros. lot, where somehow old-fashioned studio pictures are apparently still being made instead of Batman Part 6 or something -- in the year prior to life-altering changes for both of them. A stylistic pastiche of Jacques Demy and MGM and a possibly ever so slightly sardonic valentine to Hollywood itself, this is fun and boasts a few solid numbers with good choreography by Mandy Moore (!), like an opener set in the middle of a traffic jam (R.E.M. and Jake Scott did it first; actually, I guess Five Easy Pieces did) and the closing elaborate homage to An American in Paris, suffused with a feeling of just-missed true love that might have been intoxicating in that self-conscious Cinemascope frame if the story and characterizations weren't so frustratingly thin. As in Whiplash, Chazelle seems to fall over himself to find ways to make his characters fail to understand other people or the world around them. Neither the love of musicals nor the love of jazz exhibited by this film is communicated with much depth, to say nothing of Chazelle's comprehension of the actual modern music industry, but at least there's lots of enthusiasm and fluid camerawork.
The love of classic cinema is another matter; and I would be remiss if I didn't note how excited I was that a scene revolved around going to the Griffith Observatory after seeing Rebel Without a Cause... only to be immediately disappointed by how awful the musical number set within it was. But as with The Artist, the markers of affection for the art seem a tad superficial -- the difference between Fred Astaire and Ginger Rogers dancing in a gazebo and Stone and Gosling tapping lightly beside a park bench is our degree of investment, which comes from the script's broadness and lack of real wit. (There are some funny moments, mostly involving the horrors of casting.) The characters seem very much like frozen shells carted out for each scene with only the blandest of indicators that their lives have gone on since the last "fall" or "winter" title card. And perhaps it's a small thing, but a fine idea for a musical might be to have a few better than decent songs prepared before you go around bashing A Flock of Seagulls, who had songs people actually remember, not a fate I expect any of these will enjoy.