You might have come across poetry from back in the day that has lines that start "O Muse!" or "Ye Gods!" If a recently-written poem had an apostrophe to the muses or gods, you better hope it's ironic or messing around with the old style. Otherwise, that's pretty cheesy. John Keats' poem "Ode to a Grecian Urn" was written in the nineteenth century, and even he is giving the muse a hard time. Langston Hughes isn't being cheesy either, because his apostrophes are to blues music. And the blues is a muse you can get behind.
- Lines11 and 16: The speaker is calling out as if he was saying, "O Blues, why do you do this to me? It's so good that it hurts!"
- Line 14: The sweetness of this apostrophe to the Blues is a juxtaposition. The sad, rag-wearing fool that is the blues/the musician has a sweetness to it that captures the joy of letting out some emotion every now-and-then.