Alliteration
Appearance
Alliteration is the repetition of leading vowel or consonant sounds in adjacent words as in, "Peter Piper Picked a Peck of Pickled Peppers". Another example is "Do you like blue". Here the "oo" sound is repeated within the sentence. This example rhymes. Assonance includes but is not limited to alliteration with vowel sounds.
Alliteration is more a feature of verse than prose. It is used in (mainly modern) English-language poetry, and is particularly important in Old French, Spanish and Celtic languages.
The eponymous student of Willy Russell's Educating Rita described it as "getting the rhyme wrong".