One of the greatest challenges in evolutionary biology is tracing back the origins of human speech in the absence of fossilized vocal sounds. Since Darwin's (1871) landmark treatise on the evolution of spoken language and music, the search for phylogenetic precursors of these two intimately connected fields has remained a major endeavor of scientific research (ten Cate and Honing, 2023).As a prime signaling channel, acoustic communication is above all socially interactive and can take many forms in the animal kingdom, thus providing an evolutionary substrate for the emergence of human musicality and conversational speech (Snowdon et al., 2015;Levinson, 2016;Snowdon, 2017Snowdon, , 2021;;Savage et al., 2020); it is also a useful system for understanding the evolutionary processes that shape phenotypic variation. In the wake of a special issue entitled "Turn-taking in Human Communicative Interaction" (Holler et al., 2015), the present collection of 13 articles brings together 47 authors who share ideas, data and methods on the theme of vocal duetting (i.e., a coordinated vocal exchange between two individuals who alternate and/or overlap their contributions) and turn-taking (i.e., a vocal exchange based on active overlap avoidance between individuals who take turns as callers and listeners) in singing mammals.Approximately 6,400 living species of mammals populate Earth (Burgin et al., 2018).Of those that have been the subject of detailed bioacoustics analyses, only few have ...