Whether they are folk songs, lullabies, dance tunes or classical art songs, there are common structural features in song types that vary by culture and context. A song is a musical composition with vocals, often incorporating different sections that are repeated or performed with variation later. Its structure includes a melody, lyrics and accompaniments that underpin, embellish, or provide contrast to the voice.
Our study examined 118 songs recorded by 86 human societies and listened to by 750 participants in Experiment 1. While the resulting data is broad and global, the underlying sonic characteristics of these songs are similar across cultures. We show that listeners around the world share notions of what songs are suited for certain functions, and we report that musical characteristics are more predictive of these function percepts than contextual features.
In particular, songs whose melodies repeat in a strophic song form and have a second musical section called a chorus are perceived as being suitable for telling stories. The AB song form is also popular in pop music, and many modern hits use this format with its alternating verses and choruses. Similarly, lullabies are distinguished by their melodies that tend to be short and repetitive, and they have rhythmic patterns and accompaniments that are slower than those of other song types. The combination of these musical elements makes a lullaby sound slow and soothing, and it is likely that this perceptual characteristic accounts for their effectiveness as a sleep inducer.