Although the Levites sang upon many occasions in the Holy Temple, one of their most important and basic musical tasks was the daily song. Each day, the Levite choir stood atop the platform located in the Court of Israel facing the outer altar, just inside the Nikanor Gates, and sung a special song for that particular day. On the Festivals and New Moon, different songs were sung. All of these songs, with their instrumental arrangements, were performed while the morning and evening wine libations were poured out on the altar by the officiating priests. Thus the Levites accompanied the Divine service of the priests with a service of their own. They complimented each other; in many ways, the Levitical songs were as important a Temple function as the priestly service of the sacrifices itself, for the one could not function without the other. Each day, during the wine libation, the overseer of the choir stood atop one of the horns of the altar and signaled to the Levites "with a kerchief in his hand" to begin their song. At three points in their song, they would pause, when the priests would sound the silver trumpets and all the people in the court prostrated themselves before the Presence of G-d.
The order of the daily songs have a deep significance, and there is a mystical connection which each song had for the particular day it was sung. The Oral Tradition has preserved the listing of the Levitical songs that were sung each day in the Holy Temple, and various commentators and sages have explained some of the connections which can be seen between these songs and the days of the week.. (Based on Tamid 7:4)