The tune NICAEA is named after the Council of Nicaea (A.D. 325) at which church leaders began to formulate the doctrine of the Trinity to oppose the heresies of Arius. NICAEA is one of the finest tunes composed by John B. Dykes (PHH 147) and the only one of his many tunes that resembles the style of the Lutheran chorale – its similarity to WACHET AUF (613) is noted by various scholars. Dykes wrote NICAEA as a setting for Reginald's text, and ever since their first publication together in Hymns Ancient and Modern (1861), the text and tune have been virtually inseparable.

Organists should articulate the repeated melody notes clearly but tie over a number of the repeated accompaniment notes. Sing at a stately tempo with solid organ tone. Use the descant once or twice a year on festive occasions.

--Psalter Hymnal Handbook