Chant on the Vigil: Vespers for the Feast of St. James
These beautiful and haunting vespers are chanted from the version given in the Codex Calixtinus. Neither Ordinary nor Extraordinary Form of the Roman Rite, but rather from the Mozarabic Rite.
Note: an earlier version of this story erroneously stated that a diocesan patronal solemnity trumps a Sunday in Ordinary Time (see below). I apologize for the error.
As it turns out, the patronal feast of a diocese doesn’t trump Sundays in Ordinary Time – the patronal feast day is lower (#8) than Sundays in Ordinary Time (#6).
I can’t claim credit for figuring this out – a priest friend pointed to the Universal Norms for the Liturgical Year and the General Roman Calendar, handily summarized in this document from the Diocese of Springfield (https://www.dio.org/uploads/files/Worship/Liturgical_Year_and_Calendar/Table_of_Liturgical_Days.pdf)
Except in Spain it is a Solemnity for the entire country, so it would trump a Sunday in Ordinary time.