It’s rare enough that an artist can knock the socks off a crowd with both songwriting and vocal ability, but when that artist also seamlessly jumps from sunny, pop love songs to deep, dark ballads that haunt your subconscious for days, even seasoned scenesters have to stop and take notice. Firehorse, the Brooklyn-based group fronted by multi-hyphenate Leah Siegel, is performing (one of only two shows scheduled for 2012 so far) at the Knitting Factory this Wednesday. Tickets are $10 in advance and $12 at the door and available here—the single of their debut album “And so they ran faster…” is available for free on their website, but do yourself the favor and see them live. We promise your hearts will be on fire, too.