Gerrit van Honthorst, Netherlands, Baroque, b.1592 - d.1656
A young woman playing a viola da gamba
Oil on canvas, 33.07 x 26.18 inches / 84 x 66.5 cm
Private collection
Signed 'GHonthorst' (GH linked, upper right)

...for a "classic" partial view of a viola da gamba, (and quite a lot of view of the young lady.)

One of my favorite paintings - I've used it for "desktop."

I believe there have been some previous threads on the Hardanger, though, which seems the more likely instrument if it was a "trad" thing and really did have frets.

John