A powerful new voice in the alt pop scene. But what does it take to make it in the music biz besides good intentions? Luck, talent, connections, good genes? Looks like Jessica has them all. Cousin of famed singer Phoebe Snow, Pomerantz’s new demo, featuring the explosive “Rock Bottom,” carves out a place for a powerful, emotive voice in a crowded marketplace.

She’s an Ivy League grad with none of the destructive habits endemic to the music industry, “Except that I have the heart of a poet,...