Critically-acclaimed singer-songwriters Marissa Nadler and Alela Diane showcased their considerable musical talents at DC9 on Tuesday night, captivating an attentive audience with intimately stripped-down sets of folk songs. Hailing from the erstwhile gold rush town of Nevada City, CA (an apparent musical hotbed, it has also produced Joanna Newsom and Mariee Sioux), Diane alternated between a selection of songs off her latest release, To Be Still, as well as from her older records. Though she…