Here's what I found in Singing the Living Tradition, the Unitarian Universalist Hymnal published in 1993:

AR HYD Y NOS
Sleep, My Child

BANGOR
O Prophet Souls of All the Years

CWM RHONDDA
God of Grace and God of Glory

HYFRYDOL
Hail the Glorious Golden City
Years Are Coming
Earth Was Given As a Garden

LLANFAIR
Lo, the Day of Days Is Here

MEIRIONYDD
The Morning Hangs a Signal
O Young and Fearless Prophet


MERTHYR TYDFIL
O Earth, You Are Surpassing Fair

ST. DENIO
Sound Over All Waters
Immortal, Invisible