The likeness in rhyming sounds between only stressed vowels, not consonants, of two or more words that are placed successively or close to each other in a line is assonance. Assonance would also constitute sounds from different vowels of words but with same consonants.
Tone Deficit by Kevin McFadden is a fitting example of assonance, with its humour right at the heart of our topic.
Can't tell your oh from your ah? Go, go or else
go ga-ga. What, were you born in a barn? Oh.
Ah. What do you say when the dentist asks?
No novacaine? Nah. Then joke's on us, Jack:
(Tone Deficit by Kevin McFadden)
This stanza of Tone Deficit is an example of alliteration in different vowels but identical consonants. Carl Sandburg's The Hammer is an example of texts with identical stressed vowel sounds.
I have seen
The old gods go
And the new gods come.
Day by day
And year by year
The idols fall
And the idols rise.
Today
I worship the hammer.
(The Hammer by Carl Sandburg)