Fascinating question! In the story “The Metamorphosis” by Franz Kafka, Gregor experiences many human feelings and sensations, despite his physical appearance. These feelings are especially revealed during Grete’s violin playing.

During Grete’s violin playing, Gregor felt a great desire to come forth from his room and be closer to his sister. This symbolized his desire for human interaction and emotional connection. Although he spent much time in solitary confinement, this occurrence connected with him and reminded him of his need for human interaction. As the story demonstrates,  

“For him it was as if the way to the unknown nourishment he craved was revealing itself to him. He was determined to press forward right to his sister, to tug at her dress and to indicate to her in this way that she might still come with her violin into his room, because here no one valued the recital as he wanted to value it. He did not wish to let her go from his room any more, at least not as long as he lived.”

Thus, his sister’s violin music reminded him of his human need for interaction with fellow human beings. He desired to have his sister emotionally connect with him, despite his physical appearance.

As her playing continued, Gregor crept closer to his sister in order to fulfill his desire for human interaction and emotional connection. However, his physical appearance prevented him from satisfying these human needs. Consequently, Gregor was forced to remain alone and accept his isolation from humanity.