This is a picture of a Troubadour playing a Lute. The Lute is very similar to the guitar but has a bit of a different shape. Also a very popular instrument played but plucking the strings so that they vibrate.
English cittern, circa 1600. A stringed instrument dating from the Renaissance, descended from the Medieval citole, or citole. Its flat-back design was simpler and cheaper to construct than the lute. It was also easier to play, smaller, less delicate and more portable. Played by all classes, the cittern was a premier instrument of casual music making much as is the guitar today.