The Father…the Son and…the Holy Spirit.@Matthew 28:20

Unknown author, 11th Century (Ave! Colenda Trinitas); translated from Latin to English by John Chandler, Lauda Syon, Part 1, 1857.

O Lux Beata Sarum melody (🔊 pdf nwc).

Holy Trinity
Pieter C. Van Aelst (1502–1556)

All hail, adorèd Trinity;
All hail, eternal Unity;
O God the Father, God the Son,
And God the Spirit, ever One.

Behold to Thee, this festal day,
We meekly pour our thankful lay;
O let our work accepted be,
That sweetest work of praising Thee.

Three Persons praise we evermore,
One only God our hearts adore;
In Thy sure mercy ever kind
May we our true protection find.

O Trinity! O Unity!
Be present as we worship Thee;
And with the songs that angels sing
Unite the hymns of praise we bring.