3,941. The Official in Charge of the Singers

Hilchos Klei HaMikdash 7:5

The official in charge of the singers would choose singers every day to stand on the platform and sing the songs. He gave the word to sound the trumpets over the offerings. There were never fewer than twenty-one trumpet blasts sounded each day in the Temple, as follows: three when the gates of the courtyard were opened, nine over the morning Tamid and nine over the afternoon Tamid. On days when a Musaf offering was brought, nine additional trumpets were sounded over it. If Rosh Chodesh, yom tov or Rosh Hashana fell on Shabbos, with the result that three Musaf offerings were brought, trumpets were not sounded for each one. Rather, nine trumpet blasts were sounded over all of them.

Hilchos Klei HaMikdash 7:6

On Fridays, six additional trumpet blasts were sounded – three to inform the people that it’s time to stop working and three to distinguish between the holy and the secular. On the three festivals, three trumpet blasts were added when the lower gate – the one to the women’s section – was opened, and another three when the upper gate – i.e., the Nicanor Gate – was opened. It was called the upper gate because it was higher than the women’s section. Three more trumpet blasts were added when the water for the libation was filled on Succos. Trumpets weren’t sounded when the water for the libation was filled on Shabbos. Three more trumpet blasts were sounded when the water libation was poured on the altar. All of these blasts were sounded by the word of the official in charge of the singers. All of these blasts were sounded with trumpets (rather than with shofars).