How does Gregor respond to his sister's violin playing? What might Kafka be implying about Gregor by describing this reaction?

When Grete begins to play the violin in the living room, something stirs in Gregor. As he crawls out of his room drawn by the sound, "he felt hardly any surprise at his growing lack of consideration for the others; there had been a time when he prided himself on being considerate." Gregor's lack of consideration, however, is only a somewhat belated response to his family's lack of consideration for him. Having been treated with neglect, he now neglects them in return, crawling out of the room in plain view of everyone. Gregor is now free: not only does he not have to work, but he is also no longer bothered by guilt. As an insect, he doesn't seem to need much more freedom than that. He has finally escaped all the traps that had been set for him. And yet something is clearly missing from his life, consumed as it is by apathy.

Gregor poses a question: "was he an animal, that music had such an effect on him?" Ironically, the answer to this seems to be no. The lodgers rudely move away from Grete and whisper among themselves by the window. The parents are too busy watching the lodgers with anxiety to pay attention to Grete's playing. Gregor, however, is drawn to the music. The sound he hears returns him to his humanity, reminding him of his love for his sister and his desire to send her to the Conservatory. Realizing that the others don't appreciate her playing, he wants to bring her into his room and make her play for him, rekindling the bond they once had. Though Gregor is literally an animal, he is the only one who understands and feels the redeeming power of art. When he hears the violin, his past and his love for his sister come back to him. Art saves him from his apathy, reminding him of what he has been missing despite his freedom: family. Unlike the insect Gregor, in whom music brings out the best, it is the others, in failing to appreciate art, that are something less than human.