Barton McLean (b. 1938) and his wife Priscilla (b. 1942) presently reside in Austin, Texas, where Barton is director of the electronic music studio at the University of Texas. They compose in both the electronic and instrumental media, and they have formed the McLean Mix — an electronic duo specializing in live electronic performances.

Barton studied with Henry Cowell and Iannis Xenakis at Indiana University where he received his doctorate in 1972. Like many composers, Barton has written essays on his compositional and aesthetic techniques, and we shall use his writings as a point of departure to investigate his electronic works. The subtitle to a forthcoming article ("Coping with Shattered Illusions") reveals an area of electronic music that has intrigued composers since the early 1950's — 'Problems and solutions concerning live-plus-tape composition'.

"Deserts" (1949-54) by Edgard Varese, "Capriccio for Violin and Two Sound Tracks" (1952) by Henk Badings, and the "Rhapsodic Variations" (1953-54) by Otto Luening and Vladimir Ussachevsky are the earliest works of this nature, and each piece displays a different 'solution' to the problem of live-plus-tape composition. In "Deserts", for instance, Varese alternates orchestra with a musique concrete tape whereas the "Rhapsodic Variations" simultaneously combines orchestra and concrete tape. On the other hand, Badings electronically synthesizes an orchestral accompaniment on tape to play in conjunction with a solo violin. The compositional problem is twofold: timbral (electronic or concrete materials on tape) and textural (combination or separation of instrument(s) and tape). Barton McLean's aforementioned essay, along with his composition "Dimensions II" (1974), provide valuable insights with respect to these problems.

Timbral and textural unification suggest harmonic, melodic, and rhythmic structures in "Dimensions II", for piano and tape. In his essay Barton considers these elements as constituents of 'illusion', that property which creates the framework for a work of art. McLean feels that combination of electronically generated tape and acoustic instruments is poor because electronic and instrumental sonorities project conflicting illusions. Judged according to this criteria Badings' "Capriccio" exemplifies timbral conflict between the solo violin and purely electronic tape. (This is not necessarily to be interpreted as a negative statement for there are many ways to compensate for conflicting illusions, aside from the fact that a composer may purposely establish such conflicts as one structural level).

Absence of conflicting illusions leads to homogenious relations, and Barton attempts to "blur" the distinction between electronic and acoustic sonorities to "fool the listener into perceiving an image that is greater than the constituent parts... It is this blurring of the distinction between the two that creates the illusion of one unified concept." Incidentally, this is what Badings does in his "Capriccio"; the electronic tape simulates the role of a conventional orchestra to such an extent that the listener may be fooled and mistake the tape for an orchestra.

The tape for "Dimensions II" is derived totally from piano sonorities modified by tape transposition, tape echo, modulation and filtering; both traditional and piano interior sounds are employed. Consequently, the pre-recorded tape assumes various timbral characteristics, especially those of voices, organ, percussion, and string orchestra. For instance, the choral effect at the beginning of this piece was produced by tape transposition, echo and modulation of low piano strings. With respect to timbre this tape then serves a dual function. Exclusive use of pre-recorded piano helps to establish generally homogenous timbres between the tape and performer, whereas extensive electro — mechanical transformations assist in the attainment of "new" tape sonorities. All sounds in "Dimensions II" stem from piano to form timbral cohesion, thereby eliminating one of the prime causes of conflicting illusions.

Performer and tape are further integrated by sharing rhythmic and melodic motives, often making it difficult to differentiate between the two. Successions of rapid repeated notes alternating between piano and tape illustrate this technique, and massive textures evolve when repeated melodic motives are superposed. Simple tape transposition for example, is sufficient to retain motivic unity while timbral contrast is introduced, and as more eElaborate sonorous modifications are applied timbral contrast increases.

By working in this manner Barton McLean was able to consider the pre-recorded tape as an extension of the piano, a concept formulated by the early musique concrete composers. The tape of "Dimensions II" resembles the solo tape compositions of Pierre Schaeffer ("Etude Violette" and "Etude on Piano II"), Ussachevsky ("Sonic Contours") and Ilhan Mimaroglu ("Prelude No. 1"). All of these works employ tape manipulation of piano sonorities to produce "new", yet related, timbres; McLean simply extends the medium to include piano. "Dimensions II" creates a pianistic atmosphere wherein natural and transformed sounds interact to give the illusion of a super-piano.

The other commercially available electronic compositions by Barton McLean include "Genesis" (1973), "Spirals" (1973) and "The Sorcerer Revisited" (1974-75). They are purely electronic tape pieces that illustrate a high degree of motivic unification in conjunction with timbral illusion. "Genesis" is a mixture of synthesized orchestral sonorities with sounds of a more electronic nature. In addition to motivic repetitions — often via sequencers — Barton uses orchestral timbres as a basis for obtaining additional timbres, frequently by filtering and/or modulation with a low-frequency oscillator. Like "Genesis", "Spirals" also employs much motivic repetition but the timbral palate is greater. Orchestral sonorities are less prevalent in "Spirals", and electronic and vocal-like sounds appear more frequently. "The Sorcerer Revisited" is based on the well known "Sorcerer's Apprentice" by Paul Dukas, and the tape is composed of orchestral elements due to the nature of the Dukas piece. Thematic entries appear in various 'instruments' while motivic repetitions are usually played by sequencers.

The electronic music of Barton McLean exhibits strong thematic unification along with highly organized timbral structures. Both of these elements are treated in an organic fashion whereby subsidiary motives and sonorities evolve. Most important, McLean realizes acoustical differences among conventional instruments and electronically generated sounds, reflected in his treatment of timbral relations.

Priscilla McLean also received an advanced composition degree at Indiana University (1969). She is presently on the Executive Committee of the American Society of University Composers, as well as director of the ASUC Radio Series entitled Radiofast: New American Music. Like Barton, she works in both the instrumental and electronic media, and Priscilla has also written essays on electronic music. One of these, "Fire and Ice: A Query," discusses the choice of sonorous elements in an electronic composition.

The key to understand Priscilla's electronic vocabulary is her concept of the 'imago-abstract' sound — that which is suggestive of a multitude of images, ideas, etc. Although these sounds may be programmatic, they are not treated as such in a composition. It is not their programmatic quality, but rather their acoustical properties with which Priscilla works and develops. In this way the concrete image is transcended and gives way to the abstract. This was the attitude of early musique concrete composers, and Priscilla cites the environmental music of Jon Appleton and the nonsense speech in Luciano Berio's "Visage" as examples of the imago-abstract sound. Such a concept truly liberates electronic composers, for sounds must be judged according to their usefulness in a piece. For instance, if a composer wishes to filter some sounds they must possess a rather rich harmonic spectrum. Should the chosen sounds suggest definite images, such as barking dogs, jet engines, etc., it is the composer's responsibility to create a sonorous context wherein their suggestive powers are weakened or eliminated. One method would be to filter extensively the original sound. Another solution would be to follow Berio's example as in "Visage". The sonorous flexibility afforded by the imago-abstract sound is evident in Priscilla's "Dance of Dawn' (1974).

Slowly evolving sections constructed upon motivic and timbral relations characterize "Dance of Dawn". Rhythmic unification is accomplished by articulating short periodic rhythmic patterns of varying lengths while the pitch remains constant, producing variable speed tremolos. The tremolos result from amplitude modulation of oscillator signals by sub-audio pulses. Gradually the low frequency of the modulating signal is increased so that the rhythmic (tremolo) effect of the modulation is supplanted by a distinct timbral change — the harmonic spectrum is more complex. Timbre becomes a function of rhythm. Furthermore, the tremolo motives are contrasted against sustained chords; as the tremolo effect is transformed into timbral complexity, sustained pitches predominate. The aforementioned timbre-rhythm relation is now extended to include vertical pitch combinations.

Now we must relate the preceding to the imago-abstract sound. "Dance of Dawn" is a purely electronic tape consisting of vocal, instrumental and electronic timbres. It is not programmatic, but many of its sonorities are highly suggestive if taken out of the context of the entire composition. The tremolo sound discussed above, for example, seems to depict sounds of nature (crickets, birds, etc.). Because of the way in which Priscilla blends these elements, both acoustically and structurally, the images that they might normally suggest give rise to more abstract concepts.

Finally, "Priscilla's treatment of dynamics should be mentioned. She employs the entire amplitude spectrum — from practically inaudible to very loud thereby adding another dimension to the sound environment.

Barton and Priscilla McLean have managed to develop an individual approach to electronic composition, and this is critical for all composers. Their music and essays (see Discography and Bibliography) should be examined by those interested in this medium, and a brief list of supplemental readings and recordings is included for further study.