The theorbo is a plucked string instrument of the lute family, with an extended neck that houses the second pegbox. Like a lute, a theorbo has a curved-back sound box with a flat top, typically with one or three sound holes decorated with rosettes. As with the lute, the player plucks or strums the strings with the right hand while "fretting" the strings with the left hand.

The archlute is a European plucked string instrument developed around 1600 as a compromise between the very large theorbo, the size and re-entrant tuning of which made for difficulties in the performance of solo music, and the Renaissance tenor lute, which lacked the bass range of the theorbo. Essentially a tenor lute with the theorbo's neck-extension, the archlute lacks the power in the tenor and the bass that the theorbo's large body and typically greater string length provide.