Alliteration is not when words start with the same letter but, rather, when the first stressed (or accented) syllable of two nearby words begin with the same consonant sound. This means that there are basically three types of alliterations:
When nearby words start with the same consonants and the same sounds, such as “dancing dogs”, or “big boys.”
When nearby words start with different consonants but the same sounds, such as “cats and kittens” or “jungle gym.”
When nearby words start with different sounds, but have the same sounds at the beginning of their first stressed syllable, such as “normal banana” (which each have an “n” sound on the first stressed syllable) or “regular karate” (which each have an “r” sound on the first stressed syllable).
These poems include alliterations. Some may have just a single alliteration within the poem, while others may include dozens of alliterations.
Hold your horses! Kenn's the sheriff in these here parts and some of this whistle-stop is off-limits except to his deputies.
Join the posse for just one greenback a month to have the run of the place.