May 4, 2024

Songs of Indri – The “Singing Primates” From Madagascar – Feature “Uniquely Human” Rhythms

Why should another primate produce categorical music-like rhythms? Rhythm may make it simpler to produce and process tunes, or even to discover them.
Scientists from the universities of Turin, Lyon/Saint- Étienne, and the Max Planck Institute for Psycholinguistics in Nijmegen studied indris, the singing primates from Madagascar. Credit: Andrea Ravignani
Endangered types
” Categorical rhythms are just one of the six universals that have been recognized up until now,” discusses Ravignani. “We would like to try to find proof of others, consisting of an underlying recurring beat and a hierarchical company of beats– in indri and other types.” The authors encourage other researchers to gather information on indri and other endangered types, “before it is too late to witness their breath-taking singing screens.”
Reference: “Categorical rhythms in a singing primate” 25 October 2021, Current Biology.

Finding typical musical traits across types might shed light on the biology and evolution of rhythm and music. Credit: Filippo Carugati
Songbirds share the human sense of rhythm, however it is an uncommon trait in non-human mammals. A worldwide research team led by senior detectives Marco Gamba from the University of Turin and MPIs Andrea Ravignani set out to try to find musical abilities in primates. “There is longstanding interest in understanding how human musicality developed, but musicality is not restricted to human beings,” states Ravignani. “Looking for musical features in other types enables us to construct an evolutionary tree of musical characteristics, and comprehend how rhythm capabilities evolved and stemmed in humans.”
Rhythm is categorical when intervals in between noises have exactly the exact same period (1:1 rhythm) or doubled duration (1:2 rhythm). Would indri songs reveal this “distinctively human” rhythm?
Indri tunes recorded in the wild have rhythmic categories comparable to those discovered in human music. Credit: Filippo Carugati
Ritardando in the rainforest
Over a duration of twelve years, the scientists from Turin visited the rain forest of Madagascar to team up with a regional primate study hall. The investigators recorded songs from twenty indri groups (39 animals), living in their natural environment. Members of an indri household group tend to sing together, in harmonized choruses and duets. The team discovered that indri tunes had the classic rhythmic categories (both 1:1 and 1:2), in addition to the common ritardando or slowing down discovered in a number of musical traditions. Male and female tunes had a different tempo but showed the very same rhythm.

Songbirds share the human sense of rhythm, however it is an uncommon characteristic in non-human mammals. “Looking for musical functions in other types permits us to construct an evolutionary tree of musical traits, and comprehend how rhythm capabilities came from and developed in human beings.”
Rhythm is categorical when periods in between sounds have exactly the same period (1:1 rhythm) or doubled period (1:2 rhythm). Would indri songs show this “distinctively human” rhythm?
Rhythm may make it simpler to produce and process tunes, or even to learn them.