The speaker in the poem is deeply affected by the song the young Scottish woman sings, even though he cannot understand the words. It is clear from the melody that it is a somewhat melancholy, sad tune, and he begins to consider what the subject might be. The speaker imagines that the subject could be something old and unhappy, like a battle that took place long ago, or, perhaps, it is something more modern and familiar to the singer, or, finally, it could even be a song about some kind of “natural sorrow, loss, or pain.” Whatever it is does not seem to matter much, however, as the speaker is so affected by the song that he continues to remember it long after he can hear it. The fact that he cannot understand the words is likely part of what leaves the speaker so haunted by the song; this unknown quality lends the song an especially timeless, mysterious, transcendent air. The speaker is therefore able to experience the song as pure beauty and emotion, rather than as a collection of lyrics pertaining to some particular subject.

The speaker says that the Highland lass’s voice is more welcoming than a nightingale’s, even to a weary traveler who hears it and knows that it is finally time to rest. Her voice is likewise more “thrilling” than a cuckoo’s, even to a sailor on far-off seas who knows that the sound of the bird means that land is near. The Scottish woman’s song is more affecting, more inspiring of emotion than either of these, and the comparison of her voice to that of a bird firmly establishes the lass as part of nature. Her cutting and binding of grain also connects her to the earth—she is literally reaping, or harvesting, crops in a “Vale profound,” or deep valley, in the Scottish countryside where the speaker is walking. As a Romantic, Wordsworth found inspiration in the natural world, and this poem is exemplary of his work: the speaker discovers a glimpse of the sublime in the pastoral setting of which the reaper’s song forms a part.

In the end, the speaker says that he finally leaves the young woman to her work and her song, continuing on his way. However, as he climbs the hill that forms a boundary of her valley, he continues to bear the “music in [his] heart” even after he can no longer hear the woman’s voice. The last stanza of the poem begins to use past-tense verbs (e.g., “sang,” “mounted,” “bore”) rather than the present-tense verbs of the three earlier stanzas, indicating that the speaker really has left the singing woman behind and has had to move on. However, it is clear that she has so affected him that he will remember this moment and return to these emotions each time he does. The beauty of the solitary reaper’s song has imprinted itself on the speaker’s memory.