=LOVE made "866" available on May 12, 2021. With this song being around four minutes long, at 3:35, the duration of this song is pretty average compared to other songs. This track is safe for children and doesn't appear to contain any foul language, since the "Explicit" tag was not present in this track. There is only one song in 全部、内緒。 (Special Edition), so we believe that "866" is a single. In terms of popularity, 866 is currently below average in popularity. Since there is more of a neutral sound being played, this makes the track somewhat danceable.

866 テンポ

The tempo marking of 866 by =LOVE is Andante (at a walking pace), since this song has a tempo of 96 テンポ. With that information, we can conclude that the song has a slow tempo. The time signature for this track is 4/4.

866 キー

F Major is the music key of this track. This also means that this song has a camelot key of 7B. So, the perfect camelot match for 7B would be either 7B or 8A. While, 8B can give you a low energy boost. For moderate energy boost, you would use 4B and a high energy boost can either be 9B or 2B. Though, if you want a low energy drop, you should looking for songs with either a camelot key of 7A or 6B will give you a low energy drop, 10B would be a moderate one, and 5B or 12B would be a high energy drop. Lastly, 4A allows you to change the mood.