Music 680: Electronics in Performance
Fall 2004
Lecture 4: October 4, 2004

handouts
	Karlheinz Stockhausen, "The Concept of Unity in Electronic Music" article

Karlheinz Stockhausen / Mikrophonie I (1964) for tam-tam, electronics, and six performers
overview of the work
        a particular kind of interactivity
                "dual trios" of percussionist, microphonist, electronics operator
                via the shared tam-tam
                via the interdependence of the three performance roles
        introduction to the notation
                verbal explanation, onomatopoeia, and the scale of vowel brightnesses
                but also rhythmic, pitch, and gestural precision
        introduction to the form
                moment-form as a series of self-contained gestures/textures/ideas
                        variety of possible durations but all internally unified
                variable arrangement according to a form-scheme
                        specifying the general dramatic arc of the piece but not its specific sequence
                        the "Brussels form" as a worked-out realization (and a standard of performance)

issues for realization:
	filtering: what quality of filtering?
	ergonomics: how to make this viable for the electronics operators?
		can the original be improved upon?

electronics functions: amplification, panning, filtering
        audio modules and useful techniques
                amplification: quartic control
                        implement using Pd abstractions
                                inlet, inlet~, outlet, outlet~ objects facilitate creation of custom Pd objects
                                useful here since every audio function is duplicated for two musicians
                panning: constant power
                        panning front to rear as a curve between 0 and pi/2 radians
                                front output volume as cos theta
                                rear output volume as sin theta
                                [from trigonometric identity: (cos theta)^2 + (sin theta)^2 = 1]
                                        remember that Pd signal~ objects map the unit circle from 0 to 1, not 0 to 2pi!
                filtering: 
                        as an application of delay (and flanging)
                        using constructive/destructive interference to change the spectrum of a signal    
                        typically extremely short delay lengths; can be implemented with/without feedback
                                FIR filters are feed-forward; require longer delays to achieve a frequency spec
                                IIR filters use feedback; shorter delays relative to a spec, but can be unstable
                        "twicing" built-in designs for sharper filters: h[ h[ 3x -2 h [x]]]
        user interface
                MIDI fader surface
                        can't have both operators fighting over a single keyboard and mouse
                        (and indeed might even be preferable to use two separate control surfaces)
                        dual-fader-in-a-single-channel design of the original electronics
                onscreen display: slider objects, font changes, etc.
                control logic governing filter parameters
                        reducing 0-127 MIDI fader ranges to discrete filter steps
                        allowing "high bound" changes to reduce "low bound"
		possibility of automation: mockup of GERAUSCH moment

musical structure: moment-form
        division into "monadic" and "complex" moments
                most moments qualify as monadic
                        single or a small number of musical elements
                        typically either static or "punctuated"
                                contrasting center section, or contrasting / evolving conclusion
                                generally sounds exist /persist rather than evolve: material rather than process
                                        at least partly due to the nature of the tam-tam as an instrument
                                even "collage" moment only deals with 2 groups of materials (plus plucking)
                complex moments bear substantial responsibility for form
                        because of distribution in time: periodic insertions with emphasis on back-weighting
                        often involving reprises of monadic materials (X, Y, TUTTI 157)
                                intensification and reinterpretation (via reshuffling) of overall collage form
                        processual in nature: rhythmic and sonic development (cf. gradual changes in Y)
                        rhythmic/sonic connections between collaged materials (vertical and horizontal)
                                (cf. TUTTI 157)
                        as moments of focus / intensification
                                (TUTTI forte, TUTTI pianissimo)
                                strangeness (relative to other materials) as a crucial element
                                        in this case achieved through extension in time (both are long duration)
                                        and through coordination: TUTTIs are unusual in direct vertical relationship