LUX HOMINUM (1995) for computer and optional signal processor Realized in MIT Csound, with optional nGen preprocessing Arthur B. Hunkins "In him was life; and that life was the light of men." John 1:4 GENERAL LUX HOMINUM is a slow-moving, meditative work for computer realized in MIT Csound. It exists in eight variable and fixed forms. Four are written in "straight" Csound; four require the nGen preprocessor, downloadable from Csounds.com, under "Csound Utilities." External signal processing, which imparts an additional "numinous" quality to the output, is optional. LUX HOMINUM also exists in multiple versions (dating from 1994) for FM sound card and MIDI file player. The current versions are alternate realizations to those "originals." Duration (at default tempo = 60) is 11 minutes 40 seconds. Volume is soft to moderate throughout. THE EIGHT VERSIONS The orchestra and score file pairs described below are meant to be input to MIT Csound. Csound's output is a massive digital soundfile suitable for a given D/A converter and digital soundfile player. Luxgen.txt, in addition, requires preprocessing by nGen. "Luminous modulation" below refers to the modest amount of random amplitude and tone color change (the latter via variation of the "modulation index") applied to all tones in versions with "MD" in their orchestra names. Such random modulation produces something of the "numinous" quality also obtained from (optional) external signal processing. VERSIONS WITHOUT NGEN PREPROCESSING: LUXM.ORC and LUXM.SCO--a Monaural version without random variation of event start times or "luminous MoDulation" LUXS.ORC and LUXS.SCO--as above, except Stereo LUXMMD.ORC and LUXM.SCO--a Monaural version without random variation of event start times but with "luminous MoDulation" LUXSMD.ORC and LUXS.SCO--as above, except Stereo VERSIONS WITH NGEN PREPROCESSING (luxgen.txt is the basic "scorefile"): LUXMGN.ORC and LUXGEN.TXT--a Monaural version with random variation of event start times but no "luminous MoDulation" LUXSGN.ORC and LUXGEN.TXT--as above, except Stereo LUXMGNMD.ORC and LUXGEN.TXT--a Monaural version with both random variation of event start times and "luminous MoDulation" LUXSGNMD.ORC and LUXGEN.TXT--as above, except Stereo OPTIONAL NGEN PREPROCESSING The command-line format for preprocessing of luxgen.txt is: ngen luxgen.txt lux.sco . The user is responsible for preprocessing (directions for all platforms are included in the download from Csounds.com). This creates your final scorefile; name it anything you like as long as it has the .sco extension. You can optionally delete the inoperative comment lines that begin with a semicolon. THE VARIABLE ELEMENTS Several compositional parameters can either be specified by the user or be randomly varied (entry point of "notes" is the only randomly variable element). These parameters are described below in terms of their limits of variability, and as to which .orc or .sco (gen.txt) files incorporate them. Tempo is variable from 40-66, with a default of 60; in .sco (gen.txt) files. Basic pitch level (transposition) is variable between A3 (8.00 - .25) and G4 (8.00 + .58), with a default of C4 (8.00, in octave.decimal notation). This variable, gitrans, is specified in .orc files. Modulating waveform (either sine, or pseudo-triangle with harmonics one, three and five only) is also user-specifiable in .orc files--as giwave. The pseudo-triangle produces slightly richer sounds. For each modulating waveform, three "versions" (givers) are available--three unique sets of tone colors (different modulator to carrier frequency ratios). This option is also available in .orc files. Thus, including two waveforms and three "versions," a total of six arrangements are selectable. Also, all .sco (gen.txt) files permit the rearrangement of entry order of tones played on instruments 3 and 4. This will change the sequence of tone colors. Basically, any tone color number from 1-6 can be exchanged with any other; the same is true for tones 7-12. No number may be duplicated, and 1-6 must alternate with 7-12 (in stereo versions the CHANNELS "take turns": one selects from tones 1-6, the other from 7-12). The manual exchange of color numbers is time-consuming in .sco files, where PAIRS of events must be switched. A single luxgen.txt file produces the score (lux.sco) for the orchestra files that bear "GN" in their names. The sole reason for nGen processing is to randomly vary the start times of all tones except the first, within a range of eight beats--four before, four after the "normal" start. Choosing a different random seed (rs) results in another set of durations which satisfy the above requirement. (The nature of nGen requires rather devious coding to accomplish this simple task!) A NOTE ON SAMPLE RATE All orchestra files indicate a recommended sample rate of 44100. In reality, any rate above about 30000 samples per second will suffice; anything below (such as 22050), increasingly reduces fidelity and clarity. 44100 STEREO represents a problem for most machines; first defragmenting the hard disk drive to which you will write the soundfile, will guarantee maximum glitch-free speed. If the sample rate is changed, be sure also to modify kr (control rate) to equal sr / 10. OPTIONAL SIGNAL PROCESSING External, studio-quality signal processing can enhance the sonority and character of all versions of LUX HOMINUM. The composer uses a DigiTech TSR-24 true stereo multi-effects processor. Combinations of EQ, Detune, Phaser, Flange, Chorus and Delay can give appropriate enhancement. The idea, similar to that of "luminous modulation," is to create a bright, animated, yet somewhat subtle and APERIODIC effect that intensifies the image of "light." No stereo panning should be added by the processor; the only stereo image is furnished by the (stereo) soundfile itself. Thus the stereo versions require true parallel stereo processing, which preserves the original image. Lacking a true stereo processor, only a monaural version of LUX HOMINUM should be performed.