Got an answer -- it's a tagelharpa (or talharpa), which Wikipedia describes thus:

The talharpa, also known as a tagelharpa (tail-hair harp) or the stråkharpa (bowed harp), is a four-stringed bowed lyre from northern Europe. It was formerly widespread in Scandinavia, but is today played mainly in Estonia, particularly among that nation's Swedish community.[citation needed] It is similar to the Finnish jouhikko and the Welsh crwth. The instrument is still known in Finland.[1]