The terms treble and bass refer to the two major divisions of the musical spectrum. Treble refers to the higher-pitched sounds, while bass refers to the lower-pitched sounds. The division between treble and bass is not absolute, and different instruments and voices have different ranges. However, as a general rule, the treble range extends from about C4 (middle C) to C8, while the bass range extends from about C2 to C4.
Treble and bass are also used to describe different types of instruments and voices. Treble instruments include violins, flutes, and trumpets, while bass instruments include cellos, bass guitars, and trombones. Treble voices include soprano, mezzo-soprano, and alto voices, while bass voices include tenor, baritone, and bass voices.
In music notation, treble and bass notes are written on different staff lines. Treble notes are written on the middle staff line (the line that runs through the middle of the staff), while bass notes are written on the lower staff line (the line that runs just below the middle staff line).