Fernando Carulli's Dm Prelude. I used to play this at a very fast tempo because that's how I've heard everyone else do it. Then after working out on Carulli's "Tempest" at several speeds, very slow AND very fast, I decided to try this Prelude slowly and more haunting, and it worked, so that's how I recorded it. SM57 placed high onto the soundhole and another one closer to the bridge, panned 20-20 if I remember right.

Carl Franklin produced it and handled mic placement, I engineered and presented.

This was on a 1951 Salinas y Hijos flamenco guitar my ex-wife bought me for Christmas one year. What a sound! Of course "what an ex-wife!"