One of the stranger headliners of this weekend’s Pitchfork Music Festival in Chicago will be Grimes…and it is one of the things that makes the Pitchfork Festival so great is that an artist as off the beaten path as Grimes can indeed end up as a headliner. Canadian born Claire Boucher made a splash on these shores with her latest record, “Visions,” that features an intoxicating mix of helium-voice vocals, pulsing electronic beats and hip-hop, girl-group flavors. She first made her mark by releasing two cassettes in 2010 which led to her signing to the 4AD Record label and this year’s critically acclaimed album. She is also a member of the group L$D who released their first single last month called “Don’t Smoke My Blunt Bitch.” Haven’t heard it…don’t know if I want to…