Welcome to The Weekend Stream, a relaxing review of notable digital-only catalogue titles. There may be no CD or vinyl, but there's plenty of great new/old music to float you into the weekend. This week is packed with rare treasures from Willie Nelson, Was (Not Was), Sergio Mendes and more, plus a new Guns N' Roses track and a whole different way to hear the early hits of Chicago. Willie Nelson, Teatro (Deluxe) (Island/UMe) (iTunes / Amazon) Released in 1998, Teatro found Willie Nelson,