tessitura

In music, tessitura (, texture; ) is the most musically acceptable and comfortable range for a given singer or, less frequently, musical instrument; the range in which a given type of voice presents its best-sounding texture or timbre. This broad definition is often interpreted to refer specifically to the pitch range that most frequently occurs within a given piece, or part, of music. For example, throughout the entirety of Wagner's Ring, the music written for the role of Siegfried ranges from C³ to C⁵, but the tessitura is described as high because the phrases are most often in the range of C⁴ to A⁴.