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"Now we consider the Responsorial Psalm which has a history of its own.
"In a way, if you were to walk into Mass for the first time you might find the presence of a sung psalm a bit odd. Here we are reading the Word of God and suddenly another song breaks out! What is going on here. Is it another reading, is it a prayer. What is its purpose? Well let us read and see.
"The responsorial psalm or optional “gradual” comes after the first reading. The psalm is an integral part of the liturgy of the word and is ordinarily taken from the lectionary, since these texts are directly related to and depend upon the respective readings. The cantor of the psalm sings the verse at the lectern or other suitable place, while the people remain seated and listen. Ordinarily the congregation takes part by singing the response, unless the psalm is sung straight through without response. If sung, the following texts may be chosen:
"1. the psalm in the lectionary,
"2. The Gradual in the Roman Gradual,
"3. or the Antiphon or the psalm in the Simple Gradual
“History – In the early Church there was a pattern to the psalm response much like our own today. That is to say, there was an antiphon or verse sung by all followed by extended verses of a particular psalm chosen for the day with the antiphon intervening every so often by way of a response. Many of the Fathers of the Church make mention of this format. St. Augustine makes explicit mention of the practice in his sermons; likewise, St. John Chrysostom and St. Leo the Great among others. In the early days, the psalm texts were sung in their entirety. This was true even of the lengthier psalms. (Today, there are usually selected verses of the psalm used. It is rare that a whole psalm be sung unless it be brief in itself). The responsorial psalm was seen as an integral part of the liturgy with its own significance. This is in contrast to some of the other singing we have previously discussed such as the Entrance Antiphon (Introit) which was sung originally to cover a movement or fill a space of time and set a tone. In this way it existed for a purpose beyond itself. Here the chant has an importance in itself and does not exist to cover motion etc. It was seen as a moment of pious meditation, a lyrical rejoicing after the word of God had been received into the heart of the believer. Originally the deacon was the singer of this psalm and versicle. Later the task moved to the subdeacon & later still to the schola Cantorum (Choir).”
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