Given widespread disagreement on the existence and nature of musical emotions, their links to non-musical emotions, and the conditions under which they are elicited, Juslin & Västfjäll's (J&V's) attempt to specify induction mechanisms for such disputed emotions may be unwarranted or premature. Although the notion of discrete emotions has faced increasing challenges in the general emotion literature (Barrett Reference Barrett2006; Russell Reference Russell2003; Scherer Reference Scherer, Lewis and Granic2000a), it continues to prevail in the literature on music cognition. Moreover, it remains central to J&V's conceptualization. It is odd, indeed, that the basic emotions (e.g., happiness, sadness, anger, fear), which concern automatic, innate responses to highly significant stimuli (Izard Reference Izard2007; Tomkins Reference Tomkins1962), have been co-opted for emotions expressed in music and for feelings experienced while listening to music. Typical studies provide listeners with pre-selected musical materials (based on expert agreement regarding the intended emotion) and highly constrained response choices. High levels of agreement in such contexts are viewed as confirmation of similarities in the perception of emotion in music, both within and across cultures (Balkwill & Thompson Reference Balkwill and Thompson1999; Juslin & Laukka Reference Juslin and Laukka2003). Open-ended response formats would undoubtedly generate unruly individual differences. For appraisal theorists (e.g., Ellsworth & Scherer Reference Ellsworth, Scherer, Davidson, Goldsmith and Scherer2003), however, who regard specific emotions as arising from subjective appraisals of events, individual differences in affective responses are to be expected.
Bachorowski and Owren's (Reference Bachorowski and Owren2003) selfish-gene (Dawkins Reference Dawkins1989) account of vocal (nonverbal) emotion offers an alternative to conventional discrete emotions or appraisal approaches. These authors dispute the notion of emotive vocalizations as honest signals reflecting the emotional state of the signaler, even its valence. In their view, the primary function of emotive signals is to influence listeners' affect, attitudes, and behavior in ways that are favorable to the signaler. It follows that the signaling process was shaped over evolutionary time by such consequences. These consequences can be direct, arising from signal acoustics (e.g., amplitude, variability), or indirect, arising from familiarity with the signal or prior affective experiences.
Similarly, musical signals are unlikely to reflect the affective state of the composer or performer, and they may not express emotion in any simple sense. Presumably, composers and performers strive to influence the affective state of listeners–to move them or connect with them in one way or another. It is possible, then, that emotional responses to music can be approached more productively within the broad context of communication. Diversity in listeners' responses would not be surprising in view of the diversity of personal and musical histories, as well as the variable network of associations with music in general or with specific musical pieces. Indeed, when listeners are given the option of selecting from dozens of empirically derived descriptors of feelings in response to various pieces of music, relaxed, happy, dreamy, transcendent, enchanted, nostalgic, and touched are among the most frequently endorsed terms, whereas sad, angry, and fearful are among the least common (Zentner et al., in press). Nevertheless, the same listeners use such negative terms to characterize emotions expressed by the music.
Viewing music through the lens of social and emotional regulation (including self-regulation) fits with typical uses of music in everyday contexts, whether as background or foreground (DeNora Reference DeNora2000; Sloboda & O'Neill Reference Sloboda, O'Neill, Juslin and Sloboda2001). It also fits with the cross-cultural use of maternal vocalizations for regulating infant affect and promoting attachment. Mothers use a distinctly musical style when they speak to their preverbal infants (Fernald Reference Fernald1991), a style that includes individually distinctive, or signature, tunes (Bergeson & Trehub Reference Bergeson and Trehub2007). The efficacy of maternal vocal signals is evident in infants' enchantment with this speech style (Fernald Reference Fernald1991; Werker & McLeod Reference Werker and McLeod1989)–its positive affect, in particular (Singh et al. Reference Singh, Morgan and Best2002). Mothers across cultures also sing to their infants, doing so by means of a distinctive musical genre (lullabies and play songs) and a distinctive singing style (Trehub & Trainor Reference Trehub and Trainor1998). Divergent social-regulatory goals are reflected in divergent song choices, with lullabies prevailing in cultures that value calm, contented infants, and play songs prevailing in cultures that value infant vitality and expressiveness (Tsai Reference Tsai2007). Infants prefer such infant-directed singing to typical informal singing (Trainor Reference Trainor1996). They also exhibit greater engagement and more prolonged attention to maternal singing than to maternal speech (Nakata & Trehub Reference Nakata and Trehub2004), perhaps because the former is especially effective in modulating arousal (Shenfield et al. Reference Shenfield, Trehub and Nakata2003). In short, mothers' spoken and sung signals achieve the intended affective consequences.
Despite the presumption that infants are moved by music, especially vocal music, the principal index of their engagement is interest, for example, staring at their singing mother while maintaining a relatively still body and face (Nakata & Trehub Reference Nakata and Trehub2004). Ellsworth (Reference Ellsworth2003) views interest as the prototypical human emotion because of its developmental and cross-cultural ubiquity and its undeniable contribution to learning. For Silvia (Reference Silvia2008), interest is central to aesthetic emotions. Interest may help bridge the gap between the emotions of everyday musical experience and those of the concert hall. Presumably, interest, which can vary in intensity, is related to core affect (Russell Reference Russell2003), but it does not seem to occupy a fixed region on the pleasure-displeasure continuum. In principle, one could be moved by or intensely interested in a work of art that depicts or generates disturbing images.
The conception of music as a signal designed primarily to influence the affective state and behavior of listeners raises different questions than those suggested by J&V. For example, does music accomplish some of its selfish goals by making the listener feel more connected to or more disarmed by the performer or by others who are listening simultaneously? Are these feelings intensified by participatory actions such as singing or dancing? Is music more effective than other cues in reactivating emotional memories? These questions, although admittedly modest, seem much less daunting than J&V's quest for multiple induction mechanisms of musical emotions. Progress in answering these little questions could provide the impetus for tackling big questions about the origins of music.
