She clearly doesn't like the music that you play on your guitar!!!! Take note! (only joking
)
Do you have a cat flap? If not, she might be weeing by the door because she wants to let you know that she wants to go outside, or (like my cat) is making a statement that she is not happy she is being made to stay inside.
Did there used to be a litter tray near to where she is doing her buisness? Has a cat ever done its buisness there before? If a cat can smell feline poo/wee in a certain spot, she will think its normal and perfectly ok to do her buisness there.
Best way to deter her is to rub vinigar into the carpet to get rid of all of the scents. Try it, and see if it helps!
You need to use an enzymatic cleaner (like Nature's Miracle, available at pet stores) to clean the area thoroughly. Soak any floorboards or carpet in that area with it, and let it dry.
This will eliminate the smell. Once a cat has been going in a particular area, she can still smell traces there and that will trigger her to use it again. Regular cleaners don't work for this purpose, since they leave behind traces that humans can't smell but cats can.
Also, have you taken her to a vet? Any time a cat is peeing in unusual places, it should get a check-up to make sure it doesn't have a urinary problem or infection.