Gillian Weir plays the 18 Leipzig Chorales, BWV 651-668, on the newly constructed “Bach” organ at St. Thomas Church, Leipzig, where Bach is buried and was music director. The organ, completed in 2000, replicates one built by Stertzing for St. George’s Church in Eisenach, J. S. Bach’s hometown where he knew the organ and the designing done for it by his uncle, who was organist at St. George’s. Long gone, the organ was of monumental size for its date and location, with 4m and 61 registers. Also included are Fantasia in G, BWV 572 Trio No. 4 in e, BWV 528 Prelude & Fugue in b, BWV 544 Toccata & Fugue in F, BWV 540