Greg Weeks is an American singer-songwriter based in Philadelphia. His music has been described as folk, acoustic, psychedelic and experimental. He is best known as a founding member of the psychedelic folk-rock band Espers. Weeks is also a member of The Valerie Project, and has guest-recorded with many artists including Fern Knight and Marissa Nadler. In 2007, he founded the record label Language of Stone, an imprint of Drag City, along with his partner Jessica Weeks.