I wouldn’t exactly call it chant, but I have some good recommendations for some early polyphony. I really like Machaut, Leonin, and Perotin, and especially Palestrina. If you want something with a very deep sound, look up the Tallis Scholars’ album, Miserere, by Geogio Allegri. That piece is absolutely mind-blowing.
There is an interesting legend about it, involving Mozart. After the original chant (on which the allegri setting was based) was first written, the Catholic church forbade it from being written down. It was deemed so beautiful that it could only be heard twice a year, on the two most holy days of the Catholic calendar, during holy week (the week before Easter weekend, which commemorates the death and resurrection of Christ): the Wednesday before Good Friday, and Good Friday itself, the day that Jesus is said to have died on the Cross. The chant was guarded with unparalleled zeal for over 800 years as the most sacred and beautiful chant in the entire canon, and even more jealously so after Allegri turned it into a polyphonic choral piece. I will let wikipedia finish the story:
“Although there were a handful of supposed transcriptions in various royal courts in Europe, none of them succeeded in capturing the beauty of the Miserere as performed annually in the Sistine Chapel. According to the popular story (backed up by family letters), the fourteen-year-old Mozart was visiting Rome, when he first heard the piece during the Wednesday service. Later that day, he wrote it down entirely from memory, returning to the Chapel that Friday to make minor corrections…Mozart was summoned to Rome by the Pope, only instead of excommunicating the boy the Pope showered praises on him for his feat of musical genius.”
Anyway, it’s worth a listen. I hope this was helpful. What kind of chants have you listened to that you enjoyed?