tessitura

In music, tessitura ( , , ; ; ) is the most acceptable and comfortable vocal range for a given singer (or, less frequently, musical instrument). It is the range in which a given type of voice presents its best-sounding (or characteristic) timbre. This broad definition is often interpreted to refer specifically to the pitch range that most frequently occurs within a given part of a musical piece. Hence, in musical notation, tessitura is the ambitus, or a narrower part of it, in which that particular vocal (or less often instrumental) part lies—whether high or low, etc.

However, the tessitura of a part or voice is not decided by the extremes of its range, but rather by the share of this total range which is most used. Hence, it is referred to as the "heart" of a range. For example, throughout the entirety of Wagner's Ring, the music written for the tenor role of Siegfried ranges from C to C, but the tessitura is described as high because the phrases are most often in the range of C to A.