It still exists, the rock in the surf that resists all trends and all rapid change: lullabies that are passed on orally from parents to their children. “Sleep, little children, sleep” for example: a basic motif of three or four notes in descending order that has given children sweet dreams for generations. But is it really true that songs like this still sound like the grandparents once heard them from their parents?
Rather not. Because even supposedly timeless children’s songs that have been handed down orally are likely to have changed significantly over generations; in fact, different versions from different centuries are known of “Schlaf, Kindlein, schlaf”. Scientists now have exactly how something like this happens in the journal Current Biology traced. Researchers from the Max Planck Institute for Empirical Aesthetics (MPIEA) in Frankfurt am Main led by music psychologist Manuel Anglada-Tort played melodies of varying complexity to almost 1,800 test subjects online. The participants from the USA and India sang them individually. A recording of this singing was then passed on to the next subject, who imitated it again, and so on – like “Stille Post”, only with melodies.
When evaluating the recordings, it became clear that the participants had accidentally changed the tone sequences over time. “The changes were not random, but had one clear effect: they made the melodies easier to learn,” explains senior author Nori Jacoby, leader of the Computational Auditory Perception research group at MPIEA. In concrete terms, this means that interval jumps became smaller and tone sequences more arc-shaped, i.e. they tended to rise and fall more or less continuously.
Demanding songs become sequences of notes that everyone can handle
The team identified three main factors that influenced the oral transmission of melodies: biological, cognitive and cultural. “The biological limitations of our bodies affect which tunes we can sing and which we tend to avoid,” explains Jacoby. Lung volume and articulation skills, for example, play a role here. Demanding songs therefore become melodies that even those who are less musically savvy can warble.
Music psychologists understand cognitive influence to mean how well you can remember melodies: tone sequences that are difficult to remember are adapted over the years so that they can be remembered more easily. Finally, the influence of culture on the oral transmission of melodies surprised the researchers the most.
“The cultures and types of music we’ve been exposed to in our lives affect how we change music when we audition,” says lead author Anglada-Tort. Participants from the Indian group adapted melodies to the typical Indian tonality, while US participants oriented themselves more towards “Western” tone sequences. In follow-up experiments, the researchers want to investigate how people sing songs that have been influenced by different cultures. It is conceivable that, for example, a western-Indian remix of “Schlaf, Kindlein, schlaf” will be created.