Willie Nelson's sister Bobbie has passed away. She was 91 years old and was part of Willie's band for the last 50 years. Bobbie was always behind the piano and she could play some mean notes. She was always featured during the concert playing "Down Yonder." Willie has credited Bobbie many times with his success. A few years ago Bobbie released a book "Me and Sister Bobbie:True Tales of the Family Band".