Peter Quince at the Clavier and Susanna

Susanna is a rather odd story in the Apocrypha. It was not written in Hebrew (as is noted in the heading of the story in our Bible version), and it speaks up for the rights of a woman, Susanna. In the story, two elders lust after a woman, Susanna, and catch her bathing alone in a garden. Confronting her, they say that if she will not lie with them, they will say that she was meeting a young gentleman. She cries out, they testify against her, and she is sentenced to death. Before she is killed, however, Daniel speaks up in her defense, questions the elders, and they are put to death instead for bearing false witness.
Peter Quince is a character from Shakespeare's play A Midsummer Night's Dream, which is about two young couples falling in and out of love through the magic of fairies. Peter Quince is a commoner that attempts to be a playwright. He is a definite failure at it, with Nick Bottom being far better and capable. However, Nick Bottom's head is transformed into that of an ass's, and Titania (Queen of the Fairies) falls in love with him. She dotes on him for a bit, then has her lovespell lifted by the Oberon, the King of the Fairies. Nick falls asleep, is returned to normal, and wakes up saying that he has had the craziest dream, and they must write a ballad for it for the play (which is completely unrelated to the play itself; no donkeys are part of the play, nor fairies, nor even dreams).
Peter Quince at the Clavier is a symphony of words. Wallace Stevens uses imagery and wordplay to paint a musical setting, where events are represented in sounds, not words (which is rather interesting, considering that this is a poem, not a song). He claims that music is truly about emotion, not sound, and so he can paint the picture using words to invoke the image of sounds to create emotions, thereby making music. A rather indirect process, in my opinion, but interesting nonetheless. As far as what Peter Quince is doing at a clavier, I have no idea. The poem, I think, is attempting to rewrite his play with music, but goes off on a tangent about the Apocryphal Susanna tale. So I am well and truly lost. Where did Peter Quince get a clavier? And isn't the story of Susanna younger than ancient Greece and the story of Theseus? And how is Susanna relevant to his play, about two young lovers that commit misguided suicide (rather like Romeo and Juliet, you sly dog, Shakespeare)? Sooth, the only thing I can conclude is that Wallace Stevens wrote a really odd poem.