These vocalizzi were specially devised to exercise the vocal muscles and build up strength, stamina, and flexibility. Few singers know that some sixty muscles are embedded in the larynx itself for operating the vocal cords. Most of the vocalizzi are suitable for all voices; however, Nos 7, 37-45, are more for the coloratura and light sopranos, Nos 46-49 are quite exacting, but great voice-builders if employed judiciously.