1. In Temple and talmudic days, the hazzan was a general communal functionary. Since the 6th century c.e., the hazzan has functioned as the leader (cantor) who recites aloud the prayers before the congregation. Also used in contrast to Ba'al Tefillah (q.v.).
2. In Talmudic sources, the term hazzan is used for a wide range of communal officials, but most commonly denotes a synagogue official. The hazzan ha-keneset performed a variety of duties, including taking out the torah scrolls for readings, and announcing the beginning and ending times for Shabbat and festivals. In Talmudic times there was no regular office for the hazzan, any member of the congregation, including the Rabbi could act as the Shaliach Tzibur (representative of the public for prayer.) It was during the period of the geonim that the hazzan became a permanent fixture in the synagogue. With the introduction of piyyutim into the service, the hazzan was responsible for choosing appropriate moments to insert piyyutim and often composed the musical settings themselves. During the Middle Ages, the status and responsibilities of the hazzan increased dramatically. Congregations generally required that their hazzan have a pleasing voice, a comprehensive knowledge of the liturgy, and an upstanding character. The role of the hazzan today is similar in many modern congregations, though major reforms have been introduced to the tradition (only in certain congregations), including the fixed documentation of melodies used in the synagogue, official programs for the training of cantors, use of instruments, the choir etc..