Only I didn't know (With Pianist Kim Kwang Min)

Only I didn't know (With Pianist Kim Kwang Min) is a melancholic song by IU with a tempo of 134 BPM. It can also be used half-time at 67 BPM or double-time at 268 BPM. The track runs 3 minutes and 18 seconds long with a C key and a minor mode. It has low energy and is somewhat danceable with a time signature of 4 beats per bar .