The speaker describes a relationship in which they feel used and then discarded. Music here seems to stand for something the speaker gives of themselves, perhaps their voice, creativity, or affection. The other person "choked" it out of them, making a habit of demanding it, and lost patience the moment the speaker made one small mistake on a note.
The second stanza turns more painful. While the speaker was on their knees, begging to be heard, the other person no longer wanted to listen. The kneeling image shows how far the speaker was willing to lower themselves, and the dash at the end leaves the thought hanging, as if the speaker has no more to say.
The mood is raw, bitter, and sad. There is anger in the word "choked," but there is also hurt and a sense of powerlessness. The poem suggests how it feels to be valued only when you perform perfectly, and ignored when you falter.