D.O.P. made "Letter to the Old Me" available on December 10, 2018. With this song being around four minutes long, at 3:52, 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. Because this song is the only song in Letter to the Old Me and no other songs are present in the album, we classify this track as a single. In terms of popularity, Letter to the Old Me is currently below average in popularity. Even with the track produces more of a neutral energy, it is pretty danceable compared to others.
We consider the tempo marking of Letter to the Old Me by D.O.P. to be Andante (at a walking pace) because the track has a tempo of 94 テンポ, a half-time of 47テンポ, and a double-time of 188 テンポ. Based on that, the speed of the song's tempo is slow. Activities such as, yoga or pilates, can go well with this song. The time signature for this track is 4/4.
F Minor is the music key of this track. Because this track belongs in the F Minor key, the camelot key is 4A. So, the perfect camelot match for 4A would be either 4A or 3B. While, a low energy boost can consist of either 4B or 5A. For moderate energy boost, you would use 1A and a high energy boost can either be 6A or 11A. However, if you are looking for a low energy drop, finding a song with a camelot key of 3A would be a great choice. Where 7A would give you a moderate drop, and 2A or 9A would be a high energy drop. Lastly, 7B allows you to change the mood.