A new study has identified several characteristics typical of music related to sleep, such as being quieter and slower than other music. However, popular sleep music playlists on Spotify contain faster, louder and more energetic songs. Rebecca Jane Scarratt of Aarhus University, Denmark, and colleagues presented these findings Jan. 18, 2023, in the open access journal PLOS ONE.
Many say they listen to music to fall asleep, which raises the question of whether the music chosen for this purpose shares certain universal characteristics. However, research on the characteristics of sleep music is limited and previous studies have been relatively small.
To better understand the characteristics of sleep music, Scarratt and colleagues analyzed 225,626 songs from 985 playlists on Spotify associated with sleep. They used Spotify’s API to compare the audio characteristics of the sleep tracks with the audio characteristics of music from a dataset representing music in general.
This analysis showed that sleep music is usually quieter and slower than other music. It also more often lacks lyrics and more often features acoustic instruments. Despite these trends, however, the researchers found significant diversity in the musical characteristics of sleep music, identifying six distinct subcategories.
Three of the subcategories, including ambient music, match the typical characteristics identified for sleep music. However, music in the other three subcategories was louder and more energetic than average sleep music. These songs include several popular songs, including “Dynamite” by the band BTS and “lovely (with Khalid)” by Billie Eilish and Khalid.
The authors speculate that, despite their higher energy, popular songs may be able to aid relaxation and sleep for some people through their familiarity. However, more research will be needed to explore this possibility and identify the different reasons why different people choose different music for sleep.
Overall, this study suggests that there is no “one-size-fits-all” when it comes to the music people choose to sleep. The findings could aid in the future development of music-based strategies to help people sleep.
The authors add: “In this study, we examined the characteristics of music used to sleep and found that while sleep music is generally softer, slower, instrumental, and more often played on acoustic instruments than other music, the music people use to sleep has a exhibits great variety including music characterized by high energy and tempo. The study may both inform the clinical use of music and increase our understanding of how music is used to regulate human behavior in everyday life.”
- Scarratt RJ, Heggli OA, Vuust P, Jespersen KV (2023) The audio characteristics of sleep music: universal and subgroup characteristics. PLOS ONE 18(1): e0278813. DOI: 10.1371/journal.pone.0278813