<prompt> Translate the following text to EnglishHali ya kwanza ya Leonardo da Vinci, Picha ya Mwanamuziki 1485, ni mojawapo ya kazi chache za sanaa zilizobaki.  <response>: Its principal treasure, though of contested provenance, is Leonardo da Vincis luminous Portrait of a Musician 1485, unfinished but at the same time the best preserved of the masters few surviving works. 