LLANFAIR is usually attributed to Welsh singer Robert Williams (b. Mynydd Ithel, Anglesey, Wales, 1781; d. Mynydd Ithel, 1821), whose manuscript, dated July 14, 1817, included the tune. Williams lived on the island of Anglesey. A basket weaver with great innate musical ability, Williams, who was blind, could write out a tune after hearing it just once. He sang hymns at public occasions and was a composer of hymn tunes.

LLANFAIR was first published with a harmonization by John Roberts in John Parry's Peroriaeth Hyfryd (Sweet Music) (1837). The tune has been associated with the Wesley/Cotterill text since its publication with the text in The English Hymnal (1906). LLANFAIR is actually a common Welsh name, but some scholars believe that in this case the tune's name refers to the Montgomery County village in Wales where Williams was born.

A rounded bar form (AABA) tune, LLANFAIR features the common Welsh device of building a melody on the tones of the tonic triad. The tune is in a major key (not all Welsh tunes are in minor keys!). The melismas give fitting shape to the "alleluias." Use brisk accompaniment for this cheerful tune. LLANFAIR has a similar pattern to that of EASTER HYMN (388); see suggestions there for antiphonal style performance.

--Psalter Hymnal Handbook