I had known of Paco Pena as a Flamenco Guitarist for a long time but not as a composer.
A number of years ago I went to see him play in Oxford and the 'Missa' formed the second half of the concert.
I have never been in a 'classical' concert where the audience where brought to such a fever pitch that they were stamping and shouting by the end for more, and we got it!
The musical playing is impassioned and vibrant, the singing is truly awesome - and very loud in places (really crank up the sereo to hear it as it should be) and the Academy of St. Martin in the Fields Chorus' enjoyment shines through the choral sections.
As a piece of theatre this is a stunning piece combing a classical choir with flamenco guitar and drums, flamenco singing and dancing. If I had heard this on CD first I am not too sure what I would have thought, but do buy and enjoy - just listen to it a couple of times before making your mind up!
If there was a video or DVD I would definitely buy that too! (There is a DVD now but for some odd reason it only seems to be available in the US despite the fact it is English and Spanish performers and it is recorded in Spain. Check out US Amazon).