not central to the skill. One can write a perfectl yeffective computer program
for chess that will not need an yinformation about how particular chess posi-
tions or games will affect the emotions of certain human players. I think there is
a strong case for saying that a computer could never adequately simulate Louis
Armstrong without some implementation of a theor yof the emotions.
24.4 Expression and Emotion as Foundational Aspects of Musical Expertise
Those approaching music with the prejudices and preoccupations of experi-
mental ps ycholog yhave been war yof examining the emotional aspect, for
methodological and conceptual reasons. Rather than examine these reasons in
detail, I should like to point to some investigations that seem to have ‘‘opened
doors’’ into this area.
The advent of the microcomputer and microtechnolog yhas, for the first time,
made possible eas yand accurate transfer of detailed performance information
into computers for sophisticated analysis. The 1980s saw a number of studies
(Clarke, 1985; Gabrielsson, 1983; Shaffer, 1981; Sloboda, 1983; Sundberg, 1988;
Todd, 1985) that measured minute expressive variations in performance loud-
ness and timing. These studies showed several things: (1) A given player can
consistentl yrepeat given variations on successive performances; (2) these per-
turbations are not random but, rather, are intentional, and performers can alter
them to a greater or lesser extent at will; (3) man yof these perturbations are
rule-governed and relate to the formal structure of the music in systematic
ways.
M yown studies (Sloboda, 1983, 1985b), for instance, have shown that timing
deformations are organized around the strong metrical beats of tonal melodies
in a wa ythat makes the metrical structure clearer for listeners than it is when
such deformations are not present. Although we do not yet have the evidence,
this line of research suggests that all effective expression ma ybe s ystematic and
rule-governed in this way, helping to highlight musical structures in a way that
makes their emotion-bearing content more manifest to listeners.
The other line of contemporar ythinking that converges with the experimen-
tal work on expression is the music-theor ywork of such writers as Leonard
Meyer (Meyer, 1956, 1973) and Fred Lerdahl (1988a, 1988b; Lerdahl & Jack-
endoff, 1983). Meyer has convincingly argued that emotion in music arises
out of the complex, often subliminal web of expectations and violations of
expectations that musical structures unfold over time (Narmour, 1977). Lerdahl
(1988b) takes this a step farther b ysuggesting that onl ystructures that have
certain formal properties (such as discreteness and hierarchical organization)
can be directl ydetected b ylisteners (Balzano, 1980; Shepard, 1982). Onl ysuch
structures will be effective in creating the types of tensions and resolutions that
can support the emotional activities and responses peculiar to music. Lerdahl
has particularl yenraged certain sections of the avant-garde music communit y
b yclaiming that traditional tonal music satisfies his criteria, whereas such
forms as serial music do not. This could be used as an explanation of why
tonalit yhas been able to resist all attempts to oust it from center stage in
music and wh yman yavant-garde genres have but limited appeal. The general
thrust of all this thinking about music gets independent support from cognitive
Musical Expertise 575