It may use condensed or compressed form to convey emotion or ideas to the reader 's or listener 's mind or ear ; it may also use devices such as assonance and repetition to achieve musical or incantatory effects .
The author analyzes several basic forms of alliteration and assonance in du fu 's poems and points out that due to his excellent mastery of alliteration and assonance , du fu 's poems are more harmonious and musical in artistic effect .