From the YouTube entry:
"The tradition of choral music at St. Mary's Cathedral in Augsburg goes back to the 15th century, the Domsingknaben being mentioned as the Cathedral's Boy Choir for the first time in a document in the year 1439. Referring to the Cathedral's patron saint, the young boys call themselves "Marianer". The tradition of Domsingknaben was then continued until the year 1865. In 1976 Bishop Dr. Josef Stimpfle reinstated the Augsburger Domsingknaben within the diocese in their present form, affiliating them to the Diocesean School Institute for administrative purposes.
Returning to their roots, the Augsburg Domsingknaben attach particular significance to cultivating the Gregorian choral and old classic polyphonic music. The choir music of early Viennase Classic as well as the vocal music of Johann Sebastian Bach also belong to the regular repertoire of the Augsburger Domsingknaben.
The 'Missa Sancti Nicolai', written in 1772, after a decade's service at the court of Count Nicholas of Esterhazy, is a work full of pastoral charm and serene piety. Intended as a surprise gift of gratitude on the occasion of the Count's Saint's name day, first performed in the chapel of princely residence."