John Keys has produced a very extensive range of CDs of organ hymn accompaniments, voluntaries and Mass settings, in association with the bestselling popular science writer Brian Clegg .

Brian Clegg
All of the following are available from the Church Music Site, http://www.hymncds.com , Tel. 00 44 1793 737071:
(Click here to see a list of individual tracks)
Popular Traditional Hymns for All Seasons, a core set of organ hymn accompaniments on 6 CDs
More Hymns, a 2-CD set
Holy Week, Easter and Ascensiontide, a 3-CD set
Christmas Organ Accompaniments, containing carol organ accompaniments for congregations and choirs
More Christmas Organ Accompaniments
Communion Hymns: 3 individual CDs
Organ Music for Remembrance Day, including several National Anthems, The Last Post and Reveille, and hymns
Organ Music for Weddings, a 2-CD set containing organ pieces and hymn accompaniments for weddings
US Anglican Hymn Supplement, a set of 4 discs produced in association with, and under the guidance of Anglican Bishop Joel Marcus Johnson of The Chesapeake, Maryland, USA

Bishop Joel Marcus Johnson
Alternative Hymn Tunes (US) Volumes 1, 2, 3 and 4 contains hymns, many of which are specific to the American Baptist tradition
Catholic Organ Hymn Accompaniments
Methodist Organ Hymn Accompaniments Volumes 1 and 2
Seventh-Day Adventist Organ Hymn Accompaniments, available on 2 individual CDs
French and German Organ Music, a CD of organ pieces
Bach Miniatures, a CD consisting of short pieces by J.S.Bach
Organ Miscellany, volumes 1 and 2: contain pieces which are suitable for use as voluntaries, and others simply for the enjoyment of the listener
There are also CDs of piano recordings, consisting of four discs of Worship Songs and three of Junior Worship Songs.
Finally, various Mass Settings are also available.
Individual tracks can also be ordered from the full list given on the Church Music Site.
Click on the links to hear some sample tracks:
Johann Sebastian Bach (1685-1750): Toccata in d BWV 565
Vivaldi/ arr. Johann Sebastian Bach (1685-1750): Largo e spiccato (Concerto in d BWV 596)
The Marcussen organ at St Mary's, Nottingham