A Bassus partbook from a set of four volumes. A Quintus book was lost probably before 1736 when the library at Chirk Castle was inventoried; the set also has an organ book held in the library of Christ Church, Oxford, shelfmarked GB-Och Mus. 6. Copied by one main scribe, with later additions by a second scribe. The main scribe may perhaps have been William Deane, organist at Wrexham and at the chapel in Chirk Castle, whose 7 pieces in these books are unique to them. The second scribe copied a series of 3vv pieces in all the books except the Bassus, starting from the back of each book with the books upside down. Each book has a section of 17-22 folios with blank staves only between the two series of works. Probably copied in London.
The original owner was Sir Thomas Myddelton (1586-1666), of Chirk Castle (near Wrexham, Wales). Owned by Myddelton family until recent times; sold by Lt. Col. Ririd Myddelton to Richard Macnutt. Purchased by New York Public Library in 1970.