Eve made "約束" available on December 23, 2020. With this song being around four minutes long, at 4:12, 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 廻廻奇譚 / 蒼のワルツ, so we believe that "約束" is a single. 約束 is below average in popularity right now. Since there is more of a neutral sound being played, this makes the track somewhat danceable.

約束 テンポ

The tempo marking of 約束 by Eve is Andante (at a walking pace), since this song has a tempo of 80 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.

約束 キー

A♭ Major is the music key of this track. This also means that this song has a camelot key of 4B. So, the perfect camelot match for 4B would be either 4B or 5A. While, 5B can give you a low energy boost. For moderate energy boost, you would use 1B and a high energy boost can either be 6B or 11B. Though, if you want a low energy drop, you should looking for songs with either a camelot key of 4A or 3B will give you a low energy drop, 7B would be a moderate one, and 2B or 9B would be a high energy drop. Lastly, 1A allows you to change the mood.