In less than a week, Guns N’ Roses will kick off their lengthy summer tour with a leg of shows in Europe. Frontman Axl Rose got a chance to warm up his chops with a surprise appearance at Billy Joel’s concert at Dodgers Stadium in Los Angeles on Saturday night. Rose, who spent last summer fronting AC/DC, joined Rose to sing “Highway to Hell” as well as Joel’s “Big Shot”. Watch fan-shot footage below.