Medieval-style music

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.

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.