Solo musician needs infrequent studio space (oakland downtown)

Hi- I'm a solo musician and I am in need of a studio space for composing a few times a month , on the order of once or twice a week for a few hours.
Hours flexible.
I am not loud, but I will need to bring some instruments in and out or leave a keyboard there if possible.
I will need privacy, so a room in a house full of other people won't work.
rent negotiable.