Piano to Pray With, Volumes 1-3 were released by Jubal Productions in the early 2000's. The original idea was for there to be at least one hour of non-stop piano-only improvisation.
Vol. 1 had a group of intercessors in a nearby room praying, while the prayers were fed into my headphones while playing. Vol. 2 (Worship in Prayer) same concept but intentionally going through familiar worship songs in the process. Vol. 3 (Christmastide) same concept but intentionally going through familiar Christmas songs in the process.