What is a Chorus ?
A Chorus is traditionally the bit where everyone joins in - this was brought home to me one night when I was in a pub (bar) with a load of Irish lads having a sing-song ( the Irish have a strong tradition of communal singing ).
They were singing "The Ballad of Davy Crockett".
One guy would sing the verses ( he seemed to know them all - there are a lot in this song ) then the rest of them came in powerfully on the chorus - "DAVY, DAVY CROCKETT KING OF THE WILD FRONTIER" - the effect of this style of unaccompanied verse/chorus singing was really uplifting even given the slightly bizarre choice of song.
A chorus section can be any length - in the above example it is just 1 line or 4 bars.
In the Beatles song "And I Love Her" the chorus is just the title of the song - barely covering 2 bars.
" Like A Rolling Stone " by Bob Dylan has a 12 bar chorus.
Generally a more usual length for a chorus is 8 bars.
In songs where there is no " joining in " style the chorus can be identified as the bit where the lyrics repeat - in instrumental music the chorus may be a strong theme that is repeated at regular intervals.
Identify the chorus section of a song and count the bars.