Freestyle is a style of
rap, with or without instrumental beats, in which
rap lyrics are
improvised, i.e. performed with no previously composed lyrics, and "off the top of the head". It is similar to other improvisational music such as
jazz (
Myka 9 of
Freestyle Fellowship describes it as being "like a jazz solo") where there is a lead instrumentalist acting as the improviser and the rest of the band providing the beat.
Rap battles are improvised in this way.