In the sixth line of the first Stanza, we read:
“... and sings a melancholy strain...”
This “s” sound at the beginning of sings and strain has been repeated. Poets often do this. Do you know why? Do you know what this “poetic repetition” is called? Can you find instances of this in The Solitary Reaper?
Poets often repeat such sounds to make the effect more intense and ornamental. This “poetic repetition” is called alliteration.
In line 15 we find an instance of alliteration in “silence of the seas.” In line 18 we find alliteration in “perhaps the plaintive numbers flow.” Line 27 also has alliteration in “I saw her singing at her work.”