Scientific research has shown that singing may have been the primary form of        communication for early humans before the invention of language.  Singing without the aid of instrumentation is referred to as a capella - from pre renaissance Italian and it  literally means — “ in the style of the chapel “. The term is used to describe both vocal groups and soloists alike and although it refers to singing without accompanying instrumentation, a cappella often features some form of simple percussion to help keep the beat.