Instruments which are in essence simply a string or strings and a string bearer. These instruments may have a resonator box, but removing it should not render the instrument unplayable. They include the piano therefore, as well as other kinds of zithers such as the koto, and musical bows.
Bar or stick zithers (311)
The string bearer is bar shaped. 311.1 Musical bows - The string bearer is flexible. 311.11 Idiochord musical bows - The string is cut from the bark of the cane, remaining attached at each end. 311.111 Mono-idiochord musical bows - Containing one string only 311.112 Poly-idiochord musical bows or harp-bows - Containing several strings that pass over some type of bridge. 311.12 Heterochord musical bows - The string is of separate material from the bearer. 311.121 Mono-heterochord musical bows - The bow has one heterochord string only. 311.121.1 Without resonator. 311.121.11 Without tuning noose. 311.121.12 With tuning noose. 311.121.2 With resonator. 311.121.21 With independent resonator. 311.121.22 With resonator attached. Without tuning noose. With tuning noose. 311.122 Poly-heterochord musical bows - The bow has several heterochord strings. 311.122.1 Without tuning noose. 311.122.2 With tuning noose. 311.2 Stick zithers - With rigid string carrier 311.21 Musical bow/stick - The string carrier has one rigid and one flexible end. Instrument has one resonator gourd 311.22 True stick zithers - NB Round sticks which happen to be hollow by chance do not belong on this account to the tube zithers, but are round-bar zithers; however, instruments in which a tubular cavity is employed as a true resonator, like the modern Mexican harpa, are tube zithers. With one resonator gourd. With several resonator gourds.
Tube zithers (312)
The string bearer is a vaulted surface. 312.1 Whole tube zithers - The string carrier is a complete tube Idiochord tube zithers. 312.12 Heterochord tube zithers. 312.121 Without extra resonator. 312.122 With extra resonator. 312.2 Half-tube zithers - The strings are stretched along the convex surface of a gutter. 312.21 Idiochord half-tube zithers. Heterochord half-tube zithers.
Raft zithers (313)
The string bearer is composed of canes tied together in the manner of a raft 313.1 Idiochord raft zithers. 313.2 Heterochord raft zithers.
Board zithers (314)
The string bearer is a board 314.1 True board zithers. 314.11 Without resonator. 314.12 With resonator. 314.121 With resonator bowl. With resonator box - the piano is part of this subdivision. 314.2 Board zither variations. 314.21 Ground zithers. 314.22 Harp zithers.
Trough zithers (315)
The strings are stretched across the mouth of a trough 315.1 Without resonator. 315.2 With resonator.
Frame zithers (316)
The strings are stretched across an open frame 316.1 Without resonator. 316.2 With resonator.
Composite chordophones (32)
Acoustic and electro-acoustic instruments which have a resonator as an integral part of the instrument, and solid-body electric chordophones. The resonators and string bearers of these instruments are physically united, and they cannot be separated without destroying the instrument. This includes most western string instruments, including lutes such as violins and guitars, and harps.
Lutes (321)
The plane of the strings runs parallel with the resonator's surface. 321.1 Bow lutes - Each string has its own flexible carrier. 321.2 Yoke lutes or lyres - The strings are attached to a yoke which lies in the same plane as the sound-table and consists of two arms and a cross-bar. 321.21 Bowl lyres. 321.22 Box lyres. 321.3 Handle lutes - The string bearer is a plain handle. 321.31 Spike lutes. 321.311 Spike bow lutes. 321.312 Spike box lutes. 321.313 Spike tube lutes. 321.32 Necked lutes 321.321 Necked bowl lutes
The plane of the strings lies at right angles to the sound-table; a line joining the lower ends of the strings would be perpendicular to the neck. Notched bridge
