Grace Mitchell (photo: Robert Alleyne) It’s 6:30pm on Sunday and Grace Mitchell is, through no fault of her own, late to her soundcheck at The Independent. Mitchell is in town for a couple of days, opening for St. Lucia, and has agreed to give The Bay Bridged behind-the-scenes insight into her preparation process and to talk about her music. The previous evening, she ran through another abbreviated routine at The Fillmore (because headliner St. Lucia had gone longer than usual), and later posed for us in the legendary theater’s poster room. Tonight is off to a rough start: It’s pouring rain and her [...]