Victimae Paschali Laudes.
This is by Manuel de Sumaya, a Creole composer born in Mexico in the 17th century. I've been listening to his music along with some other 16th-18th century Mexican composers, like Juan Bautista Sancho,* and I'm blown away. This is an amazing musicalculture! how can people not use this music? It's amazing. hear another, Lauda Sion Salvatorem. More, hear anoter.
*Techically from California.