Oboe

Hornbostel-Sachs classification: 422.112

Oboe d'amore

Hornbostel-Sachs classification: 422.112

Oboe da caccia

Hornbostel-Sachs classification: 422.112

Ocarina

Hornbostel-Sachs classification: 421.221.42

Octave mandolin

Hornbostel-Sachs classification: 321.322

Octavin

Hornbostel-Sachs classification: 422.212

Octoban

Hornbostel-Sachs classification: 211.211.1

Octobass

Hornbostel-Sachs classification: 321.322-71

Octocontra-alto clarinet

Hornbostel-Sachs classification: 422.211.2

Octocontrabass clarinet

Hornbostel-Sachs classification: 422.211.2

Omnichord

Hornbostel-Sachs classification: 5

Ondes Martenot

Hornbostel-Sachs classification: 5

Oopoochawa

Hornbostel-Sachs classification: 122.1

Organ

Hornbostel-Sachs classification: 5

Orpharion

The orpharion is a delicate instrument, which seems like a combination of a cittern and a lute: the tuning of the lute and the metal ("wire") strings of the cittern. In fact it is a later version (and about 3/4 size) of a bandora (see under). Only two original instruments survived : the Palmer orpharion (in Copenhagen) and the Rose orpharion (in UK). It was designed in the second half of the 16th century.

The orpharion was made like a guitar, with a flat or slightly rounded back, and with a beautiful wavy outline (which fits in the outline of a renaissance lute). The rosette was carved in the soundboard (like the lute) or made of separate wood and inserted.

Oud

Hornbostel-Sachs classification: 321.321

Overtone zither