Since I'm a big fan of Hibike! Euphonium, I decided to watch the movie yesterday and this movie was just 1 hour and 43 minutes of RECAP OF THE 1ST SEASON.
Don't expect any new scenes in the movie because I can assure you that there aren't any. If you're going to watch the 2nd Season of Hibike and you've watched the 1st Season but it's been a long time since you watched the 1st Season then you can watch the movie as a refresher because all the important plot points are in the movie. Otherwise, watch the 1st Season if you want a true experience of Hibike! Euphonium or if you want to know why Asuka is best girl because the lack of Asuka in this movie is goddamn frustrating.
Oh and the credits song is the OP from the 1st Season. The difference here is it's an "Orchestra" version but TRUE is still singing the song. If you want to hear the orchestrated version of Hibike's OP 1 then go ahead and go knock yourselves out.
There's not much else to say about the movie, I suppose. It's just a recap, after all. Even though I already watched the 1st Season, I still enjoyed the movie.