Bass

The double bass, or simply the bass, is the largest
and lowest-pitched bowed string instrument in
the modern symphony orchestra.
The double bass is generally tuned in fourths.
The standard tuning is E1, A1, D2, and G2.
Throughout classical repertoire, there are notes
that fall below the range of a standard double
bass. In the Romantic era and the 20th century,
composers such as Wagner, Mahler, Busoni and
Prokofiev also requested notes below the low E.