As mentioned here previously, the Hymn Tune Introits are a way to incorporate the proper texts of a Mass in the liturgies of parishes that are very much accustomed to singing hymns. I've taken the entrance antiphons for the next two Sundays and put them into verse form.
The Missal presents as the Entrance Antiphon for the Most Blessed Trinity: Blest be God the Father, and the Only Begotten Son of God, and also the Holy Spirit, for he has shown us his merciful love.
While my versification misses some important elements of this text, particularly regarding the Son, it is certainly closer than Holy God, We Praise Thy Name, or other beloved hymns which might be chosen.
May God the Father blessed be,
And His one Son eternally,
And blest the Spirit from above:
For He has shown His gracious love.
The verse is in "Church meter" (Long Meter, Ambrosian meter), which has 4 lines of 8 syllables each, and which attempts to be, at least in the 2 and 4th feet of each line, iambic. Tunes such as Jesu Dulcis Memoria and Duke Street would be good matches.
For Corpus Christ, I have included Alleluias which are reflective of the abundant use of Alleluia in the proper introit, Cibavit eos.
He fed them with the finest wheat
And sated them, alleluia,
With honey from the rock to eat,
As a rather unusual option, perhaps a parish might consider singing this Corpus Christi antiphon to the tune Sweet Sacrament, and adding the refrain usually sung with Jesus, My Lord, My God, My All.