"ALL YOU NEED TO KNOW” BY GRYFFIN & SLANDER FT. CALLE LEHMANN OUT TODAY GRYFFIN’S DEBUT ALBUM ‘GRAVITY’ DUE OUT LATER THIS SUMMER L.A. BASED ARTIST/PRODUCER TO APPEAR AT COACHELLA NEXT MONTH. Los Angeles-based artist/producer Gryffin and L.A.-based production duo SLANDER have teamed up for a s