They make the message of the song direct and purposeful.
The short lines and repetition in the song make the message very direct. It is clear that the speaker of the poem wants his people to be let go. If the lines were long and very detailed, the listener would need to spend more effort to discern the singers message. The shortened lines give the song more power and emphasize the speaker's message.
A. cards used for keeping track of information from sources
As a noun ,
Travel arrangements are easier now than they used to be
As a verb ,
I’ll travel to Turkey next year !
