The Introit (entrance) is an ancient remnant of liturgy. As the congregation awaited the arrival of the clergy it would chant Psalms, usually many of them. In our day the Introit is reduced to just one Psalm, a portion of it, or sometimes a combination of two psalms. (On rare occasion a New Testament verse or prophet).

The Psalm is chanted "antiphonally". That means back and forth between two voices, or groups of voices. We learn this method of worship from the Seraphim in Isaiah chapter 6 who chanted "one to the other" Holy Holy Holy Lord God Almighty. St. Paul notes the same in the earliest record of New Testament liturgy we have when he says, "Speak to one another in Psalms and hymns and spiritual songs." (Eph. 5:19).

At various times and places the Introit has been chanted between cantor and congregation (our practice). But it has also been done between minister and cantor or choir and congregation etc. 

But whatever the division, to get the full effect of the Introit it is desirable to chant it by half verses, rather than full verses. Nearly all Psalms are set up in such as way that each verse states the same prayer, thought or consequence in two different ways. For example in today's Introit:

Delight yourselve in the LORD,
     And he will give you the desires of your heart.

In this way God's people surround God with their praise just like the Seraphim did in Isaiah chapter six; and "speak to one another" as St. Paul prescribes.

Because of this we will make this important change in our worship. Beginning next Sunday, September 6th, the cantor will chant the antiphonal verse (opening and closing verse by himself). Then we will split each verse into have verses, the cantor chanting the first part, the congregation the second part. All will join in the "Glory Be ..."

This will help us better understand the Psalms, and add a blessed dimension to our worship. If you have any questions please ask.