Fun around town, for $10 or less: Love Songs: Dolce Suono Chamber Music Concert Series presents Love Songs: A Valentine’s Serenade at the First Unitarian Church of Philadelphia (2125 Chestnut), 7:30PM. Free Lopez: The Lopez, The Dollyrots, and Percocettes at the North Star Bar (2639 Poplar), 8PM. $8 Jazzy: Ars Nova presents Ben Ratliff, author of the new book “Coltrane: the Story of a Sound,” speaking on jazz history at the Kelly Writers House (3805......