In the modern artform, conductors tend to hoist batons for indicating melodic curves and ornaments.
These early leaders, or cheironomers, though possessing none of the modern conducting skills developed in the 17th century, using a form of choreographed hand signals, adeptly controlled the movement of the melodic lines, producing incredibly well-synchronized performances.
It is still in use in the liturgy of the Roman Catholic Church (despite a decline of chant in the late twentieth century), of some Middle Eastern sects and in synagogues to direct the singing of liturgical songs (Hebrews probably learned cheironomy from Egyptians), and, more rarely, in some ancient Western religions.
The New Grove Dictionary of Music and Musicians comments that the method is particularly developed in traditions lacking a written notation, including Vedic, Byzantine and Roman chants.
Jewish religious cheironomy can also be found as mnemonic signs in printed Hebrew Bibles, appearing above, below and amidst the text to be sung, to guide the cantor in his rendition of Biblical readings: see Cantillation.