"Ulrica" in Verdi's Un ballo in maschera. For men, their vocal extension upwards is usually co-terminus with his falsetto, unless they are a countertenor, barbershop tenor, or its equivalent in popular music. Uses of extensions include: providing an acuto, i.e. an accented high note which may or may not be written in the score, e.g. in cadenzas, mad scenes, etc. providing a cadence in acuti, e.g. E6 at the end of "Sempre libera" in La traviata (which had in fact became a tradition if the soprano is able and the conductor allows it). ornamental purposes, usually in massive scale works, e.g. "D'amor al dolce impero" in Rossini's Armida References Musical notation Singing techniques Jazz terminology