I couldn’t figure out why the low ratings when I started watching this because the show is cute, the music is obviously going to be great - and is - with two SF9 members as the male leads. I held this opinion until the last five minutes of the show when I realized that either this show was cut short for some bizarre reason or something odd was going on. Why? Because the main focus of the show is not resolved. We are given no closure on how things turn out for the female lead on her newly reestablished path nor which of the two male leads she chose.
If you want to see a show with wonderful music, a cute storyline that may or may not have a second season, this is a good one. But if you want to see one that ties all the ends up at the end of the show, this isn’t it.