Discuss and explain the rhyme scheme of the poem."The voice" by Thomas Hardy

Thomas Hardy's poem "The Voice" has a very specific,
regular, and recognizable rhyme scheme.  Rhyme scheme, as I'm sure you know, is simply
the pattern of the rhyme in a rhymed poem.  The first line is given the indicator A, and
the next line either rhymes and is also designated with an A or has a different sound
and is designated with a B, and thus it goes.  This work by Hardy clearly has an ABAB
rhyme scheme in each stanza, with a new set of rhymes for each.  Each of the rhymes is
exact except for those in lines 2 and 4 in the first stanza--were and fair are
approximate or slant rhymes.  This distinct and regular pattern of rhyming serves to add
a steadiness and consistency to the images and themes of the poem, something for you to
examine more closely on your own.