The key roles were played by Augustus and his son-in-law Marcus Vipsanius Agrippa, in their capacity as members of the quindecimviri; Augustus participated alone in the night-time sacrifices but was joined by Agrippa for those during the day. After the sacrifices of June 3, choirs of boys and girls sang the "Carmen Saeculare", composed for the occasion by the poet Horace. This hymn was sung both on the Palatine and then on the Capitoline, but its words focus on the Palatine deities Apollo and Diana, which were more closely associated with Augustus. The hymn adds a further level of complexity to the alternation of sacrifices between Greek and Roman deities by addressing the Greek deities under Latin names.