What we sing as the Responsorial Psalm today isn’t from the Psalter at all. It’s a canticle from Isaiah—the one that ends the first set of Isaiah’s prophecies. Although there are many psalms with water imagery, the Church chooses this passage from Isaiah for the feast of the Baptism of the Lord in Year B. It’s also the Responsorial for the Third Sunday of Advent, Year C and is included in the Easter Vigil.

There are many settings available for Isaiah 12; every major publisher has at least one. Composers include Haugen, Alstott, Reza, Proulx/Gelineau, Schiavone, Inwood and others. While choosing the common psalm or an alternative psalm can very useful, I don’t think it’s such a great idea today: we’d miss the exuberant joy of Isaiah’s use of water as the symbol of God’s free-flowing salvation.

Perhaps you already have a setting of Isaiah 12 in your repertoire. Consider this: if you have, or find, a setting that you and your community like and sing with enthusiasm, plan to use it for every baptismal liturgy during the year. Some parishes have baptisms in the context of Eucharist once a month—some more often, some less often. To adopt the same Isaiah canticle as the Responsorial Psalm or a Communion song for all the community’s baptisms during the year ties them together with the Baptism of the Lord with music that stirs the heart. It’s not mere repetition, but reinforcement of the joy of salvation.