ikire's '手紙' came out on March 27, 2019. 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 知らない世界も見飽きた, so we believe that "手紙" is a single. In terms of popularity, 手紙 is currently not that popular. Although the overall vibe is very danceable, it does project more negative sounds.

手紙 テンポ

The tempo marking of 手紙 by ikire is Andante (at a walking pace), since this song has a tempo of 108 テンポ. With that information, we can conclude that the song has a moderate tempo. The time signature for this track is 4/4.

手紙 キー

This song is in the music key of B♭ Major. This also means that this song has a camelot key of 6B. So, the perfect camelot match for 6B would be either 6B or 7A. While, 7B can give you a low energy boost. For moderate energy boost, you would use 3B and a high energy boost can either be 8B or 1B. Though, if you want a low energy drop, you should looking for songs with either a camelot key of 6A or 5B will give you a low energy drop, 9B would be a moderate one, and 4B or 11B would be a high energy drop. Lastly, 3A allows you to change the mood.