Anything on Alia Vox is worth having I'd say, but then again I do worship at the church of Savall. I've got most of the catalogue (though not, as yet, Musica Notturna). Have a look at the site:

http://www.alia-vox.com/

For a flavour of the music:

Alba / A la una yo naci.

Folia Improv : Rodrigo Martinez