Fuaim is the only Clannad album on which Eithne Ni Bhraonáin served as a full-time member. She also appeared on the album Crann Ull. Eithne left Clannad afterward to launch a solo career as Enya.
While latter-day Clannad and modern-day Enya share a penchant for the ethereal, a reunion between the two don’t seem to be a priority for either. That leaves "An tu’ll" as the only time Enya took lead vocals on a Clannad song. (The liner notes of the 1993 reissue states she sang on "Buaireadh An Pho’sta", but that sounds like Máire to me.)
Clannad had already established itself as a premiere interpreter of traditional Irish music in the ’70s, but as the ’80s dawned, the group reinvented itself as a pop band. Fuaim is the bridge between the two aesthetics. Although consisting of traditional material, the arrangements steeped deeper into pop territory.
On "An tu’ll", Enya sings with a sweetness subsequently wrenched out of her atmospheric overdubbed sound. It’s as foreign as hearing Enya sing with a drum set. (That sound file comes up later in the year.)