The preparatory prayers are said at the foot of the altar; the altar is incensed, the celebrant reads at the south (Epistle) side the Introit and Kyrie. Meanwhile the choir sing the Introit and Kyrie. On days on which the "Te Deum" is said in the office, the celebrant intones the "Gloria in excelsis", which is continued by the choir. Meanwhile he, the deacon, and subdeacon recite it, after which they may sit down till the choir has finished.