The cuckoo sings in the wild islands of the Hebrides off the coast of Scotland, and the traveler on the islands reacts to the break in the silence by the "melancholy strain" of the maiden.
In another of Wordsworth's poems, the cuckoo symbolizes innocence and childhood. Here in "The Solitary Reaper," the innocent cuckoo is alluded to as having broken "the silence of the seas" and the pristine forces of the rugged islands of the Hebrides in the "springtime." However, in the harvesting season, the cuckoo is not heard by the speaker; instead, it is the melancholy song and the "thrilling voice" of the maiden who "cuts and binds the grain" that "[B]reaks the silence of the seas" on the fossil beaches.
The song of the maiden certainly must affect those who hear her stirring and "welcome notes." While there is no specific mention of how the islanders react, the speaker is profoundly moved by "the plaintive numbers" of her song, and he feels that others are affected, as well. For, he remarks upon her sweet voice as more welcome to travelers than the song of a nightingale, and he argues that her voice is more thrilling than that of any cuckoo-bird that "[B]reak[s] the silence" on the fossil beaches of the Hebrides. So affected is the speaker by her song that he remembers the music long after he has heard her, as he interprets her song as an articulation of the spirit of the area and the universal emotions of humankind.