The experience that music creates as we play it or listen to it (Dewey Reference Dewey1934/1980) has strong emotional components. How our brains connect music to emotion is less well understood (Juslin & Vastfjall Reference Juslin and Vastfjall2008; Lindquist et al. Reference Lindquist, Wager, Kober, Bliss-Moreau and Feldman Barrett2012). But the pleasure that making music gives children can help to explain why they will work to develop music-making skills – skills whose learning can also affect broader skill development (Gardiner et al. Reference Gardiner, Fox, Knowles and Jeffrey1996; Reference Gardiner2000; Reference Gardiner, Lerner, Schaimberg, Anderson and Miller2003; Reference Gardiner2008a; Reference Gardiner, Vrobel, Rössler and Marks-Tarlow2008c; Zuk et al. Reference Zuk, Benjamin, Kenyon and Gaab2014).

Facial expressions (Ekman Reference Ekman1992) that communicate genuine emotion depend on direct involvement of emotion in the control of the expressive action (Damasio Reference Damasio2010). Music-making acts should be viewed in a similar way.

As I discussed previously (Gardiner Reference Gardiner2012), Damasio's theory concerning emotion (Reference Damasio1994/2005; Reference Damasio1999; Reference Damasio2010) seems especially relevant to the relationship of music and emotion. Damasio integrates evidence from James and Lange (Reference James and Lange1922) and Cannon (Reference Cannon1929) with extensive, more-recent research to propose that emotion is deeply related to ongoing moment-to-moment activation and restoration adjustments of physiology responding to changing demands on body and brain. If one adds secondary and background emotions and mixtures that defy verbal classification to primary emotions such as fear and joy, normal experience shows no break, only changes, in emotion. Feelings make us aware of major features of our physiological emotional adjustments in ways that interact with our longer-term behavioral choices and even decision making and reasoning (Damasio Reference Damasio1999).

I will begin with several examples where activities of making music create emotional experience, then discuss emotional experiences while listening to music. Some of these examples will be more familiar than others.

Music making typically involves rhythm and always involves tempo, and these both affect emotional experience. The behavioral uses of rhythm in locomotion are especially relevant here. Repetitions within rhythmic forms can help an individual to coordinate muscular activities with more general physiological activation and recovery. Such integrated physiological coordination can aid individual capability to continue rhythmic behavior over time. Relationship between music and locomotion was important to ancient Greeks (Sachs Reference Sachs1953). Putnam Aldrich taught that to the ancient Greeks, rhythm was verb: a way of moving through time (Aldrich Reference Aldrich1958). The feelings we experience when walking rhythmically at andante rhythmic tempo, or playing music with such rhythmic tempo, include an awareness of the associated, unhurried and calm physiology of our body (Gardiner Reference Gardiner2012). Slowing or increasing the tempo in rhythmical locomotion or in music can cause related changes in the emotional experience and a related sense of absence or presence of haste.

A more subtle change in experience related to rhythm can also be experienced in both locomotion and music making. In my daily walks, my progress seems less and less hurried as I change thinking of my individual stepping acts to mentally grouping them into sets of two, then three, then four. I notice my breathing slowing and presume that my heart rate changes as well, as my sense of haste decreases. Something analogous happens when I group the individual acts in music making into higher-order groupings, for example when called upon by rhythmic notation involving so-called cut time in the last movements of sonatas by Haydn, Mozart, or Beethoven. The decreased sense of haste experienced is useful in helping to more easily produce music that moves forward rapidly.

These examples only introduce the many ways in which rhythm has been developed to interact with emotion in music making.

A second type of contribution to emotional experience as music is produced comes from reaction to the specific sounds individually and in combination that are chosen to be used for musical purposes. I will focus here on sounds used most frequently within Western music. These either convey a transient percussive quality (e.g., as produced by clapping or by striking a drum) or, following a start transient, produce a continuing rhythmic vibration so rapid that individual vibrations do not reach awareness. But we perceive changes in main frequency of vibration as involving changes in perception of pitch. Other induced modes of vibration related to perceived overtones also affect the auditory experience. The percussive or pitch-bearing sounds have been produced vocally or by instruments in many different ways (Geiringer Reference Geiringer1978; Sachs Reference Sachs1940/2006; Reference Sachs1943/2008) that can affect emotions differently. Here I will focus on choices of pitches for sounds from which music is built. The ratios of frequency between sounds when presented in sequence (during melody) affect a sense of direction of movement within the music, and also a sense of musical distance within perceived musical motion. These ratios of frequency also affect the quality and degree of harmony or dissonance as two or more sounds with the same or different pitches are presented at the same time. Modes and scales identify those pitch relationships that are allowed. The difference in emotional experience produced by combinations of musical pitches taken from a major scale and from a minor scale can be striking – major typically conveying most easily positive; minor, negative emotion. Hence, the first movement of Mozart's Piano Sonata KV 310 in A minor, written at the time of his mother's death, can convey anger and grief when played with the particular pitches of the A minor scale. But if the pitch values of only a few notes are changed slightly, as if the piece were written in A major, it would be essentially impossible to convey the same emotions available in A minor.

That music making depends on specific choices of sounds, and specific plans for organizing the production of these sounds over time is of course well understood. But emotions developed as music is performed do not come only from such basic features. As or still more importantly, they come from other details of the creational acts by which musical sounds are produced. Two performances of the same piece can express emotion very differently depending upon such other details.

In work begun in the 1970s and continued, Manfred Clynes has opened an extremely important window on the relationship of such details of music making to emotion (Clynes Reference Clynes1977; Clynes & Nettheim Reference Clynes, Nettheim and Clynes1982; Clynes & Walker Reference Clynes, Walker and Clynes1982). Here, I can only introduce this work and discuss musical implications of his earliest observations.

Clynes developed a scientific instrument to study and compare the vertical and horizontal pressures as an individual produced a pushing gesture with the finger. He compared gestures produced with no specific emotion in mind with those made when subjects were asked to express a specific emotion through the action. He compared expressions of anger, hate, grief, joy, love, sex, and reverence. And he reported that as individuals indicated they were indeed experiencing and thus expressing the emotions through the pressing acts, the nature of records they produced took on characteristic shapes. The shapes were sufficiently different across emotions but similar across subjects that the associated emotion could be established from the records themselves. Clynes also recorded muscular activities and other measures of physiology.

A detailed discussion of these initial experiments is not possible here. But they support and provide new opportunity to study scientifically how music-making acts relate to emotional experiences the acts express.

A few examples may help to clarify the implications I see in these observations.

Joy, Clynes (Reference Clynes1977, pp. 39–40) tells us, was expressed on his device by a brief strong downward gesture, then an upward rebound with overshoot, leading to a feeling of “floating” that continued until a new gesture was started. If the song “Mary Had a Little Lamb” is sung joyfully, this seems to me to involve gestures of producing and jumping off each note in a way similar to what Clynes reports, and I am aware of a slight sense of floating briefly between the notes. Children typically sing it in this way. This organization of gestures seems to me to be associated with a feeling of joy more strongly than if the notes are sung or played with more connection between them. This type of production at the piano seems related also to the joy that can be conveyed by many last movements of Haydn sonatas. It may be noted that a smile also involves upward movement and a sense of facial lightening.

Love, by contrast, Clynes reports (Reference Clynes1977, pp. 37–38), though also a positive emotion, is expressed quite differently in a prolonged smooth curve. Such a form of action could, and typically would, need phrasing over several notes, as in the love theme from “Tristan and Isolde” by Wagner. The Andante movement of Mozart's KV 311 Piano Sonata, now in F major, seems to express love more strongly with musical gestures connected as Clynes's observation implies, rather than with the greater detachment associated with joy just discussed. It is plausible that Mozart intended to express love for his mother with this second movement that follows on the anger and pain expressed in the first movement.

Turning now to listening to music (Gardiner Reference Gardiner2008b), I propose that emotions experienced are most frequently closely related to those developed as music is created. The growing research concerning mirror neurons (Rizzolati & Craighero Reference Rizzolati and Craighero2004), and the insight this work gives into empathy (Damasio Reference Damasio2010), provides support for this proposition.

An obvious potential problem with this hypothesis is that many listeners who respond to music's emotions do so even before they have developed the skills needed to produce the music with the emotional values they experience. The ways we have been discussing in which the person or people producing music specifically generate emotional experience addresses this difficulty.

Emotions related to rhythmic movement within music build upon the experience and foundation we all have regarding locomotion.

Reactions to particular musical sounds chosen for music can be especially strong when we produce the sounds ourselves and experience related physiological reactions. But for reasons still not adequately understood, the sounds chosen for music also have a potential individually and in combination to develop emotion in a listener. This has been noticed and exploited in many different ways throughout human history. Emotions related to harmony and dissonance to tension and its release, seem to have been especially important to the choice of sounds used musically (Gardiner Reference Gardiner2012).

And as I have discussed and the work of Clynes helps to demonstrate, the ways in which emotion and action may interact in music making may well not be specific to music alone. It is notable that children who cannot develop their cerebral cortex as a result of early brain damage nevertheless show emotional reactions to music (Damasio Reference Damasio2010).

Music, then, as reviewed here, demonstrates a number of ways emotion can be integrated with the cognitive development and expression of physical acts. The integration of emotion with control of action that music exploits seems widespread throughout behavior. The varieties within spoken verbal expression and touch provide familiar examples. Musical expression can provide many opportunities to study this integration.

It is also of interest that music making involves skill (Gardiner Reference Gardiner2008a; Reference Gardiner, Vrobel, Rössler and Marks-Tarlow2008c; Reference Gardiner2011). The study of relationship of emotion to this example of skillful behavior may provide useful insight into how interactions between emotions and actions affect skillful behavior more generally.