Sometimes it didn't work, but it was funny to see how much Link jerked about during cut-scenes when he played it. And the song before the third Silent Realm, Din's Power?, was funny and reminded me of my own harp skills (the lack thereof)
The harp is alright. The ocarina is better. The only instrument worse is the howling ability. At least if you get it out and start playing random notes it makes a good tune.
Personally, I enjoyed the harp. Not my favorite in the series, (that would be the Ocarina) but I did like how you had to strum to a rythm, rather than select notes.
Its ok to me that you dont get to use it much, but its beutiful to me getting to watch zelda play it and hear her sing. Soooooooo awsomeeee!!!!!!!!!!!!!!!!
The harp definitely wasn't the strong point of this game. Trying to follow those stupid glowing circles? Overall I didn't have much of a problem with it picking up my movements the major problem I had was how lack luster the melodies felt as you played them and how boring of an instrument it was to play. The only side-quest I didn't finish was the lumpy pumpkin one because if I failed the song I didn't feel the need to go back to it because the song bored me.