The octave mandolin (in the US and Canada) or octave mandola (in Ireland and the UK) is a string instrument with four pairs of strings. The strings are tuned in fifths, from low to high: G, D, A, and E. It is bigger than the mandola but smaller than the mandocello. Its design is similar to other mandolin family instruments. Most of the string pairs are unison, meaning both strings in a pair are the same pitch. However, the two lowest pairs sometimes have one string that is an octave higher than the other, with the higher string played first. Some Celtic musicians use alternate tunings, such as G–D–A–D or A–D–A–D.

Terminology

The names of mandolin family instruments differ between Europe and the United States. In the U.S., the mandola and octave mandolin are common names, but in Great Britain and Ireland, these instruments are often called the tenor mandola or octave mandola. The Irish bouzouki is a similar instrument that is sometimes mistaken for the octave mandolin. However, the Irish bouzouki has a longer scale length and a different tuning compared to the octave mandolin. Additionally, the term "octave mandola" is sometimes used in the U.S. to describe an instrument known as the mandocello.

In Europe outside the British Isles, the mandola refers to the larger instrument tuned to G–D–A–E, while the smaller instrument tuned to C–G–D–A is called the alt-mandoline, alto mandolin, mandoliola, or liola.

These differences in naming are not always clear, and the terms are sometimes used interchangeably in both regions. For example, Jimmy Moon, a Scottish instrument maker, uses both names for his instrument, while Paul Shippey, an English instrument maker, refers to his as the "octave mandolin." Confusion is likely to continue as these terms remain used in different ways.

Construction

The octave mandolin is built similarly to the mandolin. The body may have a curved back, following designs from the 18th century Vinaccia school, or a flat (arched) back, based on designs from the Gibson Guitar Corporation, which became popular in the United States in the early 20th century.

The scale length of the octave mandolin is longer than that of the mandolin and varies more widely, ranging from 19 inches (480 mm) to 24 inches (610 mm), with 21 inches (530 mm) being most common. The internal bracing is similar to the mandolin and mandola, featuring a single horizontal brace on the top just below the oval sound hole. On modern instruments, X-bracing is sometimes used.

Like other mandolins, octave mandolins may have either a single oval soundhole or a pair of "f" soundholes. The number of frets on an octave mandolin also varies widely, from as few as 17 to as many as 24, with 18 or 19 frets being typical.

Since the mid-20th century, some makers have created octave mandolins with guitar-shaped bodies, such as the "hourglass" or "figure 8" designs. These instruments are built similarly to acoustic guitars, using comparable woods and internal bracing. However, the neck is much narrower and is designed to hold the mandolin’s string arrangement, rather than the traditional six strings of a guitar.

Like the mandolin and mandola, the octave mandolin has four sets of two strings each. The two strings in each set are tuned to the same pitch. Some alternate tunings use octaves instead of unisons for certain sets, but this is more common on the Irish Bouzouki.

Tuning and range

The standard tuning for an octave mandolin uses pairs of strings that are tuned to the same pitch. The standard tuning is GG, DD, AA, EE, from the lowest to the highest string.

• Fourth (lowest) pair: G2 (97.9989 Hz)
• Third pair: D3 (146.832 Hz)
• Second pair: A3 (220.000 Hz)
• First (highest) pair: E4 (329.628 Hz)

The instrument’s range is typically about three-and-a-half octaves. The exact range depends on the number of frets on the instrument. With 18 frets, the range extends from about one and one-third octaves below middle C up to A5/B5, which is in the octave above middle C. With 24 frets, the range can reach as high as E6.

Usage

Octave mandolins are sometimes used in mandolin orchestras instead of mandolas. This allows mandolin players to avoid learning to read music in the alto clef. Music for the octave mandolin is usually written in the more familiar treble clef and is played an octave lower than the notes shown (see octave clefs).