Abstract: This paper proposes that in the course of evolution
pitch structure became a human specific tool of communication the
function of which is to induce emotional states such as uncertainty
and cohesion. By the means of eliciting these emotions during
collective music performance people are able to unconsciously give
cues concerning social acceptance. This is probably one of the
reasons why in all cultures people collectively perform tonal music. It
is also suggested that tonal pitch structure had been invented socially
before it became an evolutionary innovation of hominines. It means
that a predisposition to tonally organize pitches evolved by the means
of ‘Baldwin effect’ – a process in which natural selection transforms
the learned response of an organism into the instinctive response. In
the proposed, hypothetical evolutionary scenario of the emergence of
tonal pitch structure social forces such as a need for closer
cooperation play the crucial role.