Edwin has the ability to track Querig, and Wistan uses him to find the dragon. A baby dragon bites Edwin while he is held by the ogres. According to Sir Gawain, due to this wound, "the desire will be rising in [Edwin's] blood to seek congress with a she-dragon. And in turn, any she dragon near enough to scent him will come seeking him" (174).

It is this desire to find another dragon that causes Edwin to sing and become agitated. As he and Wistan meet Axl, Beatrice, and Gawain at Querig's mountain, Edwin's singing becomes even more impassioned, turning into a shout until he "fell silent, slumping down onto the ground, and appeared on the verge of tears" (279).

After Wistan kills Querig, Edwin becomes much calmer and stops hearing the voice of his mother, which has been leading him towards the dragon. Ishiguro describes how "exhaustion swept over [Edwin]" and how after Edwin attempts to speak to his mother, "There had been no answer, and he felt a great emptiness opening within him" (299). As Edwin calms down and no longer hears the voices that had been guiding, it seems clear that he was drawn towards Querig by these voices and in her absence they have now ceased.

In terms of the thematic meanings of Edwin's singing, you may want to think about how it relates to other recurring ideas in The Buried Giant. Edwin believes he is tracking his mother rather than the dragon, and Axl and Beatrice also set out with the intention of trying to find a lost member of their family. Further, Edwin also thinks he is lying to Wistan and leading him towards his mother rather than the dragon. After Wistan tells him he has "the hunter's gift," Edwin thinks, "It was then the deception had begun" (217). In a novel concerned with dislocation and deception, Edwin's belief that he is tricking Wistan into helping him rescue his mother is certainly a ripe area for thematic investigation.