Music today is ubiquitous, highly valued, multifaceted, and plays many different roles in many different social contexts. This chapter discusses traces of musical activity that date back to 40 kya (40,000 years ago), connecting them with ideas about human behavioral modernity. It outlines the debate surrounding the evolutionary status of music. Researchers have conceptualized music as an adaptation, by-product, exaptation, and technology, and debate surrounding music's evolutionary status is heated. The chapter briefly outlines a socio-cognitive niche construction perspective, drawing on examples from the ethnomusicological literature. It emphasizes gene-culture co-evolution. The chapter focuses on examples from the ethnographic record in order to illustrate some of the myriad ways in which musicality is expressed in hunter-gatherer life, taking a broader niche construction perspective. Traditionally, the Blackfoot and Sioux tribes of the North American plains, nomadic hunter-gatherers, utilized music daily, in ritual activities and puberty rites, social activities, and war dances (promoting out-group dissonance).