The tune for Morning Has Broken is named Bunessan. The tune had been found in L. McBean's Songs and Hymns of the Gael, published in 1900. Before Eleanor Farjeon's words, the tune was used as a Christmas carol, which began Child in the manger, Infant of Mary, translated from the Gaelic lyrics written by Mary MacDonald. The English-language Roman Catholic hymnal also uses the tune for the hymn, This Day God Gives Me.

Writing credit for Morning Has Broken has occasionally been erroneously attributed to Cat Stevens, who popularized the song. The familiar piano arrangement on Stevens' album, Teaser and the Firecat (1971) was performed by Rick Wakeman, the classically trained keyboardist with Yes