Medieval-style music

Any recording of the Terra Nova Consort on Dorian Records.
The one called Renaissance en Provence is stunning.
I've played some tracks on this disc to demo systems at the HE2003 and a lot of people really liked them.

Along with Slipknot1, I would recommend the whole Gothic Voices series on Hyperion, as they specialize in the period you're looking for. I particularly like "The Earliest Songbook in England", but there are about 10 of interest, all with reasonably good sound. "The Spirits of England and France" is a 5-volume series (at least), the first 3 of which had just that title, and the last 2 had subtitles of polyphonic masses.

MA Recordings has several early Spanish volumes, all with MA's recording quality: "Danzas Medievales Espanolas"," Calamus", "Salterio" (not quite as good sound), and if you go into the 15th century, "Mudejar".

On a Veritas label - "Les Premieres Polyphonies Francaises XI Siecle", by the Ensemble Gilles Binchois.

Certain of Anonymous 4 recordings, e.g. "Miracles of Santiago", and also several of Jordi Savall's recordings cover Spanish music of this period.

Some good recommendations have already been posted. In addition to the Hildegard von Bingen recording on Hyperion (a must have) and the general recommendation to consider anything on the Harmonia Mundi label that strikes your interest, I'll offer the following specific recommendations from my LP collection that are superb both musically and sonically (you'll have to see if they are available on CD if that is your preference):

If you like music of medieval Spain, try anything by Gregorio Paniagua (dir.) and the Atrium Musicae de Madrid. For me, all of the following are "must have":

* La Spagna (Bis)
* Musique Arabo-Andalouse (Harmonia Mundi)
* Tarantelle (Harmonia Mundi)
* Villancisos (Harmonia Mundi)
* La Folia (longterm audiophile favorite; rollicking good fun and a bit bizarre) (Harmonia Mundi)

Performances by the Clemencic Consort on Harmonia Mundi are wonderful. I particularly value:

* Camina Burana (from the original manuscript, in 5 volumes on LP. Vol. 5 is my favorite, or choose the highlights disc)
* Dances Anciennes de Hongrie
* Dances Du Moyen-Age
* La fete de l'ane (Feast of the Ass)

Other miscellaneous recordings that are excellent and well worth seeking out include:

* The Dante Troubadours, Martin Best (Nimbus)
* Troubadour Songs and medieval Lyrics, Hillier (Hyperion)
* Songs & Dances 1200 to 1550, Kalenda Maya (Simax)
* Music of the Four Seasons, Joculatores Upsalienses (Bis)
* Early Music at Wik, Joculatores Upsalienses (Bis)
* Skogen, Flickan och Flaskan (Woods Women and Wine), Joculatores Upsalienses (Bis)
* Worcester Fragments,Stevens/AccademiaMoteverdiana (Turnabout)
* Sumer is icumen in - chants medievaux anglais, Hilliard Ensemble (Harmonia Mundi)

Good luck in your continuing exploration of ancient music!

Between Flex's and Rushton's recommendations, you got yourself a very comprehensive list. They nailed it!. La Spagna is a bit hard to find since it's out-of-print.

If you're interested in 12th century French polyphony in addition to secular music, another well-known cd from Harmonia Mundi is "The Age of Cathedrals", with Paul Hillier and the Theatre of voices.