The player’s breath is directed against a lamella or pair of lamellae which periodically interrupt the airflow and cause the air to be set in motion.
|Reeds / Hornbostel Sachs No#:|
|412.122||Sets of Percussion Reeds||Earlier Organs|
|412.131||Individual Free-Reeds||Bawu / Pitch Pipe / Party Horn|
|422.12||Sets of Oboes|
|422.31||Single Pipe / Free Reed|
|422.32||Double Pipes / Free Reed|
|422.22||Sets of Clarinets||Clarinets|
|422.112||Conical bore||Oboe, Bassoon|
|422.212||With Conical Bore||Saxophone|
|422.3||Reed-Pipes / Free Reeds|
The air-stream is interrupted periodically
412.1 Idiophonic interruptive aerophones or reeds – The air-stream is directed against a lamella, setting it in periodic vibration to interrupt the stream intermittently. In this group also belong reeds with a ‘cover,’ i.e. a tube in which the air vibrates only in a secondary sense, not producing the sound but simply adding roundness and timbre to the sound made by the reed’s vibration; generally recognizable by the absence of finger-holes.
412.11 Concussion reeds – Two lamellae make a gap which closes periodically during their vibration.
412.12 Percussion reeds – A single lamella strikes against a frame.
412.121 Independent percussion reeds.
412.122 Sets of percussion reeds. – Earlier organs
412.13 Free-reed instruments feature a reed which vibrates within a closely fitting slot (there may be an attached pipe, but it should only vibrate in sympathy with the reed, and not have an effect on the pitch – instruments of this class can be distinguished from 422.3 by the lack of finger-holes).
412.131 Individual free reeds – Bawu, Party Horn, Pitch-Pipes.
412.132 Sets of free reeds.
Accordica (mouth organ)
Accordolin (mouth organ)
412.2 Non-idiophonic interruptive instruments.
412.14 Band reed instruments – The air hits the sharp edge of a band under tension. The acoustics of this instrument have so far not been investigated.
412.21 Rotating aerophones the interruptive agent rotates in its own plane and does not turn on its axis.
412.22 Siren, Bull-Roarer & Corrugaphone – Whirling aerophones, the interruptive agent turns on its axis.
422.3 Reed-pipes with free reeds – The reed vibrates through at a closely fitted frame. There must be finger-holes, otherwise the instrument belongs to the free reeds 412.13.