Lute

http://en.wikipedia.org/wiki/Lute
generally to any plucked string instrument with a neck (either fretted or unfretted) and a deep

round back, or more specifically to an instrument from the family of European lutes.

Lutes were made in a large variety of sizes, with varying numbers of strings/courses, and with no permanent standard for tuning.

European Lutes:
   .....

    Cittern

   .....

African Lutes:
   .....

Asian Lutes:

   .....

    Pipa
    Qinqin

   .....

 Lute - "Greensleeves"
http://www.youtube.com/watch?v=G6wZa53B1Rc

Oud
http://en.wikipedia.org/wiki/Oud
is a pear-shaped stringed instrument

The modern oud and the European lute both descend from a common ancestor via diverging paths.
The oud is readily distinguished by its lack of frets and smaller neck.

said chraibi - Oud
http://www.youtube.com/watch?v=87sUyJ-lDYI

Orpharion
http://en.wikipedia.org/wiki/Orpharion

Greensleeves, played on a Orpharion
http://www.youtube.com/watch?v=6OiSl-qSJzY

Cittern
http://en.wikipedia.org/wiki/Cittern 

Three short pieces for the Cittern - Tommy Johansson

http://www.youtube.com/watch?v=Pp0kQXUCNxY

Portuguese Guitar (Guitarra Portuguesa)
Greensleeves
http://www.youtube.com/watch?v=xdGCVK--eEs

Robert de Visée Prélude et Allemande, Jonas Nordberg, theorbo
http://www.youtube.com/watch?v=qeUcGD4rRRc

"Kapsberger" for Theorbo played by N. Amos

http://www.youtube.com/watch?v=YEGioEyoGPY