Figure 1. Singing Reproduction Paradigm.

A. Tsimane’ territory. Map shows the four villages in which the experiments in this paper were conducted. Inset shows the region where many Tsimane’ villages are located. B. We reached the villages Mara and Moseruna by truck from the town of San Borja (left). The upriver villages of Iñañare and Anachere were reached by canoe (right). C. The Tsimane’ maintain a traditional way of living, but occasionally travel to nearby towns (e.g. San Borja) to trade and buy goods, and thus typically wear clothing from industrialized society. D. Experimental paradigm. Participants heard sequences of two tones and sung back a reproduction of what they heard. E. Spectrograms showing example stimulus and response. Stimuli were typically pure tones in a particular frequency range. Participants sung back two notes within their singing range. F. Photographs of experimental setup in the field. Experiments were generally conducted under communal roofed structures that we selected to be distant from other community activities on the days that we tested, to minimize noise. G. Experimental session. Participants listened to tones via closed headphones and sung into a microphone. A translator (here in an orange shirt) provided verbal instructions to participants. Related to Figure S1.