An example can be alliteration or the slavic antithesis or similar. Very
often these pieces of writing were poems such as epic poems that would
be sung to the people who were most often illiterate. Writers and poets
would have to sing the entire epics to listeners which is why these
devices are used. They make it easier to remember because they act as
formulas that the poet can follow like a pattern and by repeating them
all the time and changing some events and names he could remember more
or if he forgets they would give him time to make something up and make
up for the losses.
