THE SHORT VERDICT:
Short, breezy, and polished, Soundtrack #1 is a friends-to-lovers nugget of a drama that should scratch that drama itch nicely, particularly if you:
(a) like Park Hyung Sik &/or Han So Hee;
(b) enjoy friends-to-lovers stories; &/or
(c) just want something quick and easy as a drama snack.
Really quite satisfying, for a short little thing of just 4 episodes of 45 minutes each.