This is a stringed instrument with a rich history of more than 200
years, but rarely seen, and even less often played correctly, at
least in the last 50 years or so. In appearance, it is very much like
an acoustic guitar, but with some type of hollow extension emerging
from the upper (bass) bout, with a number of additional unstopped
strings that may be tuned to a specific key and plucked individually.
There are many different designs, with the most famous being the
Larson Brothers’ Dyer Symphony harp guitars. It is known that Charles
Knutsen received a patent for a “certain new design for a harp-guitar
frame” in 1898.