Double Bass

The Conrabass (コントラバス), also called the string bass, contrabass, upright bass, or simply bass, is the largest and lowest-pitched bowed string instrument. A musician who plays the double bass is known as a “double bassist”.

Tuning
The double bass is generally tuned in fourths, The standard tuning (low to high) is E–A–D–G, starting from E below second low C (concert pitch). This is the same as the standard tuning of a bass guitar and is one octave lower than the four lowest-pitched strings of standard guitar tuning.

Scoring
Double basses are most often found in symphony orchestras, chamber orchestras, concert bands, jazz bands, and other string ensembles. Double basses are never included in marching bands, even as part of the front ensemble, in favour of bass guitars. Bass music is typically notated one octave higher than sounding to avoid excessive ledger lines.

The double bass is the only commonly used string instrument in the Kitauji High School Concert Band, which otherwise consists of only wind and percussion instruments, though guitars, bass guitars, and harps are not unheard of. There is typically only one string bass per concert band, and the bassist is considered a member of the bass section.

As portrayed in Sound! Euphonium
Midori "Sapphire" Kawashima is the only string bass player in the Kitauji concert band for the main anime series.

In The Second Turbulent Movement Volume 1 and Sound! Euphonium: The Movie - Our Promise: A Brand New Day, a second contrabass player, Motomu Tsukinaga, is introduced in Kumiko's second year at Kitauji High School.

Trivia

 * The four main bowed string instruments are the violin, viola, cello, and the double bass. The first three instruments are almost never used in concert band music.
 * Some basses have a low “C” extension that, when added, allows the E string to go to a low C string.
 * The octobass is actually the lowest instrument in the string family, but there are only 2 playable replicas in the world.