[Kolokotronis]

Troparion in the 3rd Tone:

“Thou didst excellently dispense the Word of God,/ endowed with discretion of speech, O Hierarch Gregory:/ for by thy life thou didst set the virtues before us,/ and dost radiate the brightness of holiness ./ O righteous Father, pray to Christ our God to grant us His great mercy.”

Kontakion in the 8th Tone:

“We praise thee, God-inspired harp of the Church and God-possessed tongue of wisdom;/ for thou didst prove to be an image and model of the Apostles and didst emulate their zeal./ Wherefore we cry to thee: Rejoice, O Gregory the Dialogist.”

In Orthodoxy we celebrate his feast on March 12. He was, by the way, the author of my favorite Orthodox devotion, the Liturgy of the Pre-Sanctified Gifts which we celebrate throughout Great lent on Wednesday evenings.

[Salvation]

From another thread:

 

Gregorian chant radio here.

Direct link to streaming audio feed from site above.


 

[ELS]

In Orthodoxy we celebrate his feast on March 12.

That is also his feast day in the traditional Catholic calendar. I don't know why his feast day was changed. Today in the traditional calendar is the feast of Pope St. Pius X.