Responsorial psalmody primarily refers to the placement and use of the Psalm within the readings at a Christian service of the Eucharist. The Psalm chosen in such a context is often called the responsorial psalm. They are found in the liturgies of several Christian denominations, including those of Roman Catholicism, Lutheranism and Anglicanism.
The "responsorial" aspect is used in two related but different ways: the liturgical position of the psalm as a 'response' to the first (Old Testament) reading, and one possible manner of reciting it. The RSCM summarises these two aspects: "It is responsorial because it is sung in response to the first reading, not because it has a refrain or response for the people to sing. The whole psalm is therefore the response."[1]