Psalterium
a very simple stringed instrument of a triangular shape, and a somewhat similar one of a square shape were designated by the name of psalterium
Anglo-saxon harp
The Anglo-saxons frequently accompanied their vocal effusions with a harp, more or less triangular in shape,—an instrument which may be considered rather as constituting the transition of the lyre into the harp. The representation of king David playing the harp is from an Anglo-saxon manuscript of the beginning of the eleventh century, in the British museum. The harp was especially popular in central and northern Europe, and was the favourite instrument of the German and Celtic bards and of the Scandinavian skalds.
Rotta
A representation of David playing on the rotta, from a psalter of the seventh century in the British museum (Cott. Vesp. A. I). According to tradition, this psalter is one of the manuscripts which were sent by pope Gregory to St. Augustine. In the rotta the ancient Asiatic lyre is easily to be recognized.