Nobuo Uematsu's music to Final Fantasy V is spectacular. Though some say it lacks the scope of the music of Final Fantasy IV, VI, or VII, it still provides many memorable tracks.
FFV OSV is a complete soundtrack, right down to several short (10-20 second) piano tracks at the end of the second disc. About half of the songs are standard Final Fantasy fare - not bad by any means, but they pale in comparison to the other half of the tracks, which are excellent. "Mambo de Chocobo" is the best rendition of Chocobo music ever. "Fighting Gilgamesh" is some of the best battle music ever put in an RPG. "The New Origin" is exhillarating - you can't tell until 6 or 7 seconds into the piece whether it's in minor or major chords.
The main theme of Final Fantasy V, "Ahead on our Way", has generated some critisism due to being very upbeat, but this is unsubstantiated. It is no less meaningful than the themes from Final Fantasy VI or VII.
All in all, the music of Final Fantasy V is on par with the rest of the series. I recommend playing the game first - indeed many criticisms of the music come from those who have not played the game - but even without playing the game the soundtrack can be enjoyed.