tessitura explained
The range within which a vocal or instrumental part predominantly lies, as opposed to its total range
In Depth
Tessitura is more important than total range for determining whether a part suits a particular voice or instrument. A soprano aria might have the same total range as a mezzo aria, but if its tessitura sits higher — meaning most of the notes cluster near the top of the range — it demands a soprano voice. A part that sits consistently at the extremes of an instrument's range is said to have a high or demanding tessitura. Comfortable tessitura is essential for sustainable vocal health.
Wagner's Brünnhilde role has a tessitura so relentlessly high that few sopranos can sing all three Ring operas in a single cycle without vocal damage.