BuxWV136 Präludium C dur_sg, Dietrich Buxtehude prelude, virtual organ, James Pressler, first organ work in the BuxWV catalog. For all these pieces the letters after the underscore_ are the abbreviation of the virtual organ, in this case, St. Georgenkirche. I believe it's this one:
www.milandigitalaudio.com/instruments/baroque/1721-st.-georgenkirche-silbermann/
