The scale/mode used in the Tientos is pretty much the Dominant Phrygian scale. Experiment and try to create your own improv. Remember if it sounds good it can't be wrong!
The Video below shows you the chords of the tientos
Video of Right Hand Technique of Tientos:
The backing tracks include a rhythm intro and an ending (except for A Major Latin)
The loops are at least 5 minutes long so you can really jamm along.
So you will receive 24 files (220MB)
Here are 12 HQ Backing Tracks encoded at 256 kbps:
Backing Tracks Preview:
Video of Scale for Tientos: