Valentine's Day can be challenging for everyone out there, whether you've got a special someone to impress or not. The choices are limitless, and it can be hard to set something up that everyone will enjoy. This year, why not please the whole crowd with a just-before-Valentine's Day show starring local indie pop songstress Autumn Sky and up-and-comer Tre Burt?     Miss Sky, who recently won the Sac Show award for best Acoustic Show, holds a Valentine's Day show each year. 2009's show at Luna's Cafe drew a huge crowd, where patrons and audience members alike sat on floors and laps to fit in the tiny room. This year will prove to be no less of a good time, especially considering t