Explications of the concept of music usually begin with the idea that music is organized sound. They go on to note that this characterization is too broad, since there are many examples of organized sound that are not music, such as human speech, and the sounds non-human animals and machines make. One might say that music is the art of organized sound, but this is also too broad, since much poetry is organized sound, yet not music. Roger Scruton suggests that a musical sound, or ‘tone’, ‘is a sound which exists in a musical "field of force"’ (1997, 17). This is circular unless we can distinguish musical from non-musical ‘fields of force’. Scruton does so by claiming that in music we hear each sound as pitched, that is, as occupying a place in a certain structured division of the octave (that is, in a scale). (See also S. Davies 2003b.) Though certainly a central principle of musical organization, not all sounds are pitched. Even in paradigmatic classical symphonic works there is untuned percussion, and electronic works may consist entirely of white noise. A further problem with Scruton's conception of ‘tone’ is that it is a subjective phenomenon, dependent on a listener's imaginative metaphorical application of certain concepts to the sounds one hears. Since presumably a radio broadcasts music even in a forest when no one is around to hear it, this cannot be correct.
Jerrold Levinson escapes the problem of subjectivism by locating the music-making features of the sounds in the intentions of the person organizing them. The sounds must be organized ‘[i] for the purpose of enriching or intensifying experience [ii] through active engagement (e.g., listening, dancing or performing) with the sounds [iii] regarded primarily, or in significant measure, as sounds' (1990b, 273). The third condition is intended to exclude such things as poetry, since we regard the sounds of poetry in significant measure for their semantic content. It should be noted that this requires us to define what it is to regard something ‘as sound,’ since the expressivity of music might be considered a kind of semantic content and as significant a focus of attention in some music as the meanings of words are in poetry. (See sections 3 and 4, below.) Perhaps simply excluding linguistic sounds explicitly is an easier way to avoid the counterexample of poetry.
The first condition of Levinson's definition above is surprisingly aesthetic in character, given his rejection of aesthetic definitions of art in general. (See, for example, Levinson 1989.) Levinson notes the possibility of a definition of music modeled on his intentional-historical definition of art, but suggests that a more traditional definition of music is more plausible than such a definition of art in general, since the music world remains more conservative than the art world in general (1990b, 274 n. 8). It is not clear that this is quite to the point. There's nothing very radical about practicing scales, yet in doing so, one is presumably not organizing sounds with the aim of ‘enriching or intensifying’ anyone's experience. One might instead come up with a definition of music modeled on one's preferred definition of art, be it institutional, cluster, hybrid, or whatever. (See Dickie 1997, Gaut 2000, and Stecker 1997, respectively, for examples of these kinds of definitions.) Some of these approaches, such as the institutional and intentional-historical, will require less attention to the issue of the intrinsic nature of musical sounds, while others, such as the cluster and hybrid, may have to grapple directly with it, due the varying centrality of intrinsic features of the art in question to the different kinds of definition. (See Adajian 2007, for an overview of the definition of art.)
John Cage's 4'33" is a central test-case for any definition of music. It raises the question of whether organized sound is even a necessary condition on something's being music (any more). It should be noted that though the piece is often referred to as ‘silent’, Cage intended (and most musicologists take) the content of the piece to be the sounds that occur during the performance, rather than the silence due to the performer's inaction (S. Davies 1997a). Nonetheless, we can consider a hypothetical silent piece, where the audience is supposed to listen to the silence of the performance, rather than the inevitable sounds in the hall, which would be considered distractions, as in the performance of a more typical work. (Actual examples arguably include Alphonse Allais's "Funeral March for the Obsequies of Deaf Man" and Erwin Schulhoff's "In Futurum" from Fünf Pittoresken.) Levinson seems to consider both the actual 4'33" and a silent piece to be limiting cases of the organization of sound, noting that the silences of traditional works are as much as part of their organization as the sounds (1990b, 270, n. 3). Stephen Davies, on the other hand, argues that Cage goes beyond the limits of music with his piece, since ‘[w]here sound is organized, however loosely, there must also be the possibility of ambient sound, of sound excluded by the manner of organization’ (1997a, 24). Cage's piece is art, but not music, according to Davies — a work of avant-garde ‘performance art’. A truly silent piece would meet Davies's criterion, and thus presumably count as music for Davies. Of course, if one jettisons the necessity of being organized sound for being music (adopting instead an institutional definition, say) one might argue that Cage's piece is music on other grounds (because of the role it plays in the music world, for instance).
In most of this entry, the discussion focuses on ‘pure’ or ‘absolute’ music — instrumental music that has no accompanying non-musical components. Most of the philosophers whose work is discussed below also put the focus here, and there are three reasons to do so. The first is that pure music often presents the most difficult philosophical problems. It is less puzzling how a musical setting of a maudlin text could be expressive of sadness, for instance, than how a piece of music without even a programmatic text could be, since the emotional expression could somehow be transferred to the music from the text. The second reason is that, though the problems are more difficult, the solutions are likely to be more easily evaluated in the pure case. Just as apportioning blame is easier when one person is responsible for a crime than when the blame must be divided between a number of conspirators, a solution to the problem of musical expressiveness will be more clearly successful if it can explain cases of the expressivity of pure music. Thirdly, it is certain that the musical expressiveness of pure music will play a role in the expressiveness of ‘impure’ music. Though a text may be able to impart some of its expressiveness to a song, for instance, the musical elements of the song must play some role. A maudlin text set to a jauntily upbeat melody in a major key will clearly not have the same overall expressivity as the same text set to a plodding dirge. Though I have used expressivity as an example here, these same points will apply to discussions of musical understanding and value. There may also be interesting questions to be asked about the ontology of ‘impure’ music, but it is not clear they will be of the same kind as those to be asked about expressivity, understanding, and value.
Given the global prevalence of rock music, broadly construed, it is plausible that song is the most common kind of music listened to in the contemporary world. Film and other motion pictures, such as television, are also ubiquitous. There has been some significant work done on the aesthetics of song (Levinson 1987, Gracyk 2001, Bicknell 2005), music drama (Levinson 1987, Kivy 1988b, 1994, Goehr 1998), and film music (Carroll 1988, 213-225; Levinson 1996c; Kivy 1997a; Smith 1996). (On hybrid art forms more generally, see Levinson 1984.) However, it seems that there is plenty of room for further work on the aesthetics of impure music. ‘Muzak’ is another musical phenomenon that is ubiquitous, yet has received little serious attention from aestheticians, being used primarily as an example to elicit disgust. Whether or not there is anything interesting to say about Muzak philosophically, as opposed to psychologically or sociologically, remains to be seen.