Whiplash
Whiplash preceded LALA Land in the creative collaboration between the writer/director Damien Chazelle and composer Justin Hurwitz. An aspiring drummer meets a hard driving foul-mouthed teacher at the best music school in the USA. You feel like getting lashed for most of film.
Only in the end of this jazz motion picture do you understand why people hav been raving about it, giving it even higher scores than LALA Land. The ending is one of the best finales I have seen. It is truly a “grand finale.” Go see it yourself, especially if you like music.