For information on the synthesizer-enhanced pipe organ and other instrumental "tools" used here, go to John Seboldt's Synthesizer and Organ page.  

"Psalm 139: Domine, probasti", Monte Mason

as broadcast on American Public Media's Pipedreams, Program 0333, August 18, 2003, with introductory comments and context-setting selection by Michael Barone

broadcast listing here 
listen to full program here (RealAudio)

Gregorian Singers, Monte Mason, director 
John Seboldt, synthesizer 
James Frazier, organ 

Recorded at the Cathedral of Saint Paul, St. Paul, MN 
(1963 Aeolian-Skinner gallery organ, spec here)

Released on Pipedreams Premieres,
a CD of new works featured on 
Pipedreams (American Public Media)

 The most ambitious project undertaken in my early days with the Ensoniq VFX-SD synth. It was also performed (same forces) at the regional AGO convention in Sioux Falls, SD at St. Joseph Cathedral.

After the broadcast of this recording, the Fourth Presbyterian Church, Chicago music series expressed interest, necessitating the preparation of an annotated score with complete instructions on running the synth track on the specific synth. Though we didn't hear from them, we presume it went well because, as Monte said, "Chicago is still on the face of the earth..."

From the CD's notes: 

MONTE MASON'S Psalm 139: Domine, probasti was first performed in 1983 as part of a set of three choral pieces, named New Wave Psalms. It was the middle piece and totally unlike the other two. The ink was not even dry, so to speak, when THE GREGORIAN SINGERS sang it at St. Mark's Cathedral in Minneapolis, which commissioned the work. The work had been "in progress," not to mention "in limbo," for a few years until it was revived in a performance in June 1991, when the choir sang it in Sioux Falls, South Dakota, for the regional convention of the American Guild of Organists. JOHN SEBOLDT collaborated with the composer to realize a new instrumentation with a synthesizer, the result of which you hear in this recording. The work is patterned in style, orchestration, and form after the gamelan music of Indonesia, but in fact it receives its inspiration from the music of Monteverdi. The free interchange of Latin and English texts is based entirely upon an illogical approach to language and to the fact that the text iself is so mysterious that either language has the same ability to support the music.
Improvisation, "Meditation on Prospect"
from Hymnfest: Some Assembly Required,, July 25, 1998, Annunciation

(Full hymnfest here)

Here, John plays organ and synthesizer, with some degree of homage to the style of Paul Halley as he plays with the Paul Winter Consort at the Cathedral of Saint John the Divine, New York. The organ is played live; the synth utilizes mostly a repeating 8-bar programmed sequence, with the capacity of removing or adding various instruments "on the fly". In the room, instrument sounds play in dialogue with each other from front to back (speakers available on both ends of building!)

 The early American tune Prospect (Southern Harmony) is often associated with the text: 
The lone wild bird in lofty flight 
Is still with Thee, nor leaves thy sight.
It also shows up lately associated with a wonderful text by modern writer Brian Wren, "How Wonderful the Three-In-One", which names our Trinitarian understanding of God entirely gender-neutral, but beautifully!  This was the cue for this improvisation, which followed the singing of the hymn by all in the original program.
from Dueling Keyboards, April 18, 1993, Annunciation:

Tortoises and The Elephant from Carnival of the Animals, Camille Saint-Saëns

 Frank Winkels, organ; Larry Reynolds, piano; and John Seboldt, synthesizers bring some unique touches to these popular items. As Frank said about the program when we were done: "That was great - we only exceeded the bounds of good taste five times." Complete program of the concert here.

Broadcast regionally, ca. 1994, on "Artists in Concert," Minnesota Public Radio