I've had this 2-cd set for a while now, and absolutely love it. I adore Biber's music, and the Mystery Sonatas, with their beautiful, spiritual and faith-imbued resonance just go straight to the soul. The Mystery Sonatas, or Die Rosenkranz-Sonaten to give them their proper name, are presumed to have been written around 1676, but were unknown until 1905 - absolutely astonishing.
Each sonata relates to one of the fourteen Mysteries, with a concluding Passacaglia for solo violin which finishes off the set. The sonatas are divided into three groupings:
Five Joyful Mysteries
Five Sorrowful Mysteries
Five Glorious Mysteries
Each of the sonatas, relating to each of the Mysteries depicts a theme of its own. Much of the music on the violin is played using scordatura, which brings a most unusual and unique tone to the playing, and helps to make Biber's music technically difficult to play (and well worth listening to, both for its technicality, and for its beauty).
This set with Musica Antique Koln under Reinhard Goebel is, in my view, absolutely top-notch. There is not one element of the playing that I would look to have changed; the tone is beautiful, the music is played sympathetically and proficiently. I never, ever, tire of hearing these beautiful pieces and would recommend them thoroughly to anyone interested in Biber's music, or any late Baroque music.