The document discusses the variable hymns Troparia and Kontakia sung in Orthodox Christian liturgy. Troparia come before Kontakia and honor God or a saint of the day. Both hymns originated from Hebrew sources and psalmody, but began to take poetic forms in the 3rd-7th centuries composed by monks and clergy. Authors like Romanos the Melodist and those from the Melodist school developed the poetic structure and theological content of these hymns to instruct and inspire believers.