From Liber Fratrum Cruciferorum Leodiensium, given as "Fantasie de Wilhelmo Brouno". According to Apel, he was almost certainly English. Of note is the raised dominant leading tone at the final cadence, something very evocative of Pieter Cornet's music.
Played on manual II: 8,4,2,1-1/3 (the left half of the sesquialtera)