Pitchfork announced Friday that Ms. Chan Marshall’s bringing her band to The Showbox. When Cat Power played First Avenue’s ancient theater in November of 2006, Marshall had a hard time keeping her pants zipped up, and left the stage for a few minutes, returning to explain to the audience how many times she hurled. All was forgiven when she closed the set with a smokin’ rendition of “Satisfaction.”Cat PowerWhen: April 11Where: The ShowboxWatch: An audio slideshow of Cat Power’s last stop at The Showbox.