Considering Space in Music

William Moylan

Professor, Music and Sound Recording Technology

University of Massachusetts Lowell  (USA)

ABSTRACT

1. Introduction

2. Background

    The spatial qualities inherent to music recordings primarily function at two basic levels of the music’s structure (Moylan. 1986.).  Each of these levels has distinct and unique spatial qualities.  These qualities contribute greatly to shaping the music at these two primary levels of dimension.  It is common to have spatial elements or relationships of spatial qualities that exist or function between these two primary levels, and to have spatial qualities that exist or function at lower levels; these two levels dominate production usage and listener perception, and serve as a meaningful reference and point of departure. (Moylan. 1992. pp. 55-61)
    These two primary levels can be defined as the dimensions of (1) the overall sound of the recording/music and (2) the qualities and relationships of the individual sound sources or groups of sound sources contained in the recording/music. (Moylan. 2007. p.239)
    The spatial elements that exist at these two dimensions are outlined in Table 1.
 


Table 1. The spatial qualities of music recordings organized into the two primary structural levels.

2.1    Spatial Qualities of the Overall Sound

    The spatial qualities of the level of the overall sound are (1) the characteristics of the perceived performance environment and (2) the dimensions of the sound stage.
    The perceived performance environment (PPE) is the overall space where the music ‘performance,’ the music ‘recording’ is heard as taking place; it is the environment of the sound stage.  The characteristics, or dimensions, of the perceived performance environment are the result of any environmental characteristics that have been applied to the overall program, and/or the environmental characteristics of important, prominent or unique sound sources.  These qualities are static, and do not change; the dimensions of the PPE might unfold, being gradually presented to the listener over time, but the environment does not change.  This brings the PPE to establish a context for the music: an overall space within which the listener ‘hears’ the piece of music as existing.

Figure 1.  Spatial Elements of the Overall Sound of Music Recordings.     

The sound stage is the singular area occupied by all of the sound sources of the music, as an aggregate or group.  It has an apparent physical size of width and depth that are defined at the level of the individual sound source: (1) the dimension of width is defined by the furthest right and left sound (lateral localization) and (2) the dimension of depth is defined by the most distant sound source and the closest sound source.  The size of the sound stage can be fluid, with the potential to change size throughout the music (bringing the listener to different relationships to the music); the sound stage also has the potential to establish and maintain a stable context for the music, with a fixed area within which all of the musical activity is perceived as taking place.

Figure 2.  Individual sound sources placed on a sound stage.

2.2    Spatial Qualities of Individual Sound Sources or Groups of Sound Sources

    Individual sound sources in music recordings will be placed on the sound stage at a specific distance from the listener (distance location), and at a specific location in the stereo field (lateral location).  Further, the lateral image will have a width that can vary from a very narrowly defined point in space up to a size that can occupy the entire potential 90-degree span of the stereo sound stage.  A group of sound sources can have the same qualities, and be placed as an ensemble on the sound stage.
    All sounds or groups of sound sources have the potential to be placed in their own individual environments.  The qualities of the environment fuse with the sound quality of the sound source to create an overall timbre to the sound, and also to provide the illusion of its placement in a unique physical space.  The physical spaces can have dimensions that defy our natural physics (Moorefield. 2005. p.xv.), or can be quite realistic; they will impart a quality of depth to a sound, but actual distance location will be defined by the detail present in the sound source’s timbre (Chowning. 1977. p.50).  The characteristics of environmental cues are can be reduced to the time, amplitude and frequency anomalies of the reflections of the direct sound in the captured or created environment. (Moylan. 2007. pp. 10-15, 195-200.)

3.  Some Fundamental Analysis Questions

    The fundamental questions for evaluating the impact of spatial characteristics in music (music recordings) are broad, encompassing the most far reaching and the subtlest detail.  This offering of a point of departure for understanding centers around the understanding that spatial qualities can be characterized by (1) the qualities of their states of being—as unchanging attributes and dimensions—and by (2) the activity of any of the spatial characteristics, as exhibited by either individual sources, groups of sources, or the overall texture.  
    This approach is also concerned with how spatial qualities can serve to create a context for the piece of music or for musical materials, and how they can to provide enhancement of musical materials or ideas.  It can also be extended to the possibility that spatial qualities have the potential to be or to generate musical materials in and of themselves (Tenney. 1986. p.89).  It is important to remember that the term ‘spatial qualities’ refers to all of those outlined in Table 1, and that any of those qualities may be more active or more significant at any point in time, and at any structural level.

Table 2 is a rudimentary outline to begin exploration.

Table 2.  Some fundamental questions towards evaluating the spatial qualities of recorded music.

4.  Exploring the Roles of Space in Music—At the Level of Individual Sound Sources

    This section will examine the roles of space in music at the level of the individual sound source, or groups of sound sources.  This structural level is also where musical materials (melodies, harmonies, rhythms, etc.) exist in their most complete and immediate forms.
    We will examine several different recordings and versions of The Beatles’ “While My Guitar Gently Weeps” to explore the qualities of various spatial elements in the music, and examine their impacts.

4.1    Distance location

    Distance is the perceived location of the listener in relation to the music, the sound stage, or to an individual sound source.  In creating or capturing a music recording, sounds become placed at a distance to the listener.
    The amount of distance can play a significant role.  Its impacts can be manifest in the listener’s connection to the music and the musical material, the immediacy of the musical message, and a sense of context for the sound stage and the musical texture.

Table 3.  Several potential impacts of distance location.


In these ways we can have our perception of the physical presence of the voice and instruments, coupled with their musical materials transformed.  The listener can be brought into a physical relationship to the music in a unique way; they can be drawn into becoming part of the ‘story’ (music) or observing the ‘story’ (music) from some distance.  Either way, the relationship imparts an impact on the musical experience.

Figure 3. Sound source locations, beginning through first chorus of “While My Guitar Gently Weeps,” LOVE version.

For the LOVE version of “While My Guitar Gently Weeps”, the distance locations of the George Harrison’s lead vocal and Gibson J-200 guitar pull the listener into an intimate relationship to the musical material and the message of the music.  There is a sense of closeness in these parts and the solo cello line during the material through the first verse that is dramatically different from those of the string parts of the chorus.  In the chorus the sound stage changes in width and depth, although the distance locations and relationships of guitar and vocals do not change markedly.  Careful attention will reveal subtle changes to the environmental characteristics of Harrison’s vocal, note: this is not a change of distance location—it is a change of the sound quality of the vocal’s host environment.

Now let us compare this to the ‘White Album’ version of “While My Guitar Gently Weeps.”


Figure 4. Sound source locations, beginning through Verse 1 of “While My Guitar Gently Weeps,” ‘White Album’ version.

Note the extreme change of distance location of Harrison’s Gibson J-200 acoustic guitar and the lead vocal in comparison to the distance locations we observed in LOVE.  They are no longer in the area of proximity that is very close to the listener, within the listener’s personal space (Moylan.  2007.  p. 190-191).  Do these different qualities of distance bring each version to communicating something different?  Or do they bring each song to communicate the same message differently?  It is clear the “poignant, meditative, and somber” version of “While My Guitar Gently Weeps” from LOVE is profoundly different musically from the “raucous, electric” version on the ‘White Album’ (Hertsgaard. 1995. pp. 252-253).
    The question remains: just how do the dimensions of distance location and sound source size and location bring the listener to a different relationship to—and understanding of—the music and its message?  And how do these factors shape music’s substance?

4.2    Lateral imaging to enhance music

    The placement of sources along the width of the sound stage brings lateral imaging.  Sounds are provided with locations and size.
    In the both of the above versions of “While My Guitar Gently Weeps” the lead vocal is mixed to the center of the sound stage, but the ‘White Album’ vocal image is considerably wider.  In this way it remains quite prominent in the mix although it is at a greater distance than the LOVE version mix, and also at a lower loudness level.  Consider though:

•    Does the width of the lead vocal in each version contribute in other ways?  
•    Does this image width bring the vocal more prominence or significance, merely provide an ornamental embellishment, or contribute to the music or its texture in some other way?

General observations regarding image size and location would begin with identifying:

•    Where are the sound sources on the sound stage?
•    Where are the musical materials on the sound stage?
•    What size are the sound sources?
•    What size are the musical materials?

This could lead to pertinent observations of image size, using the following table for a beginning.

Table 4.  Image size in music.



Table 5.  Image locations.


Table 5 brings fundamental questions regarding location of sources.  These two tables explore potential ways imaging can enhance, extend the character, or provide ornamentation to musical ideas.  The impacts are potentially profound, and these tables are but a humble starting point for exploration and inquiry.  These tables, as well as distance location can be used for blending or fusing sounds (and their musical ideas) with similar treatments, and various degrees of dissimilar treatments can bring various degrees of contrast, distinctiveness, prominence, etc.

4.3    Lateral imaging as musical idea

    Image location can be extended to be a primary musical idea in itself.  Recordings have incorporated ‘rhythms of locations’ into musical fabrics.  In these instances, rhythms are created by the locations of sounds on the sound stage; patterns of locations are presented to the listener, and the repetitions and alterations of these patterns can create musical interest just as the patterns of changing pitches, timbres or harmonies.
    Drum solos are common places for rhythms of locations, functioning in parallel with the specific drum and cymbals of the passage.  In practice this can be extended to repeating the same sound (or different sounds from the same source) and establishing a pattern of soundings from different, specific locations.  This as evidenced in the ‘cash register’ sounds of the surround version of “Money” by Pink Floyd (2003).

4.4    Unique environments for any sound source

    Music recordings can, and often do, place individual sound sources (or groups of sources) in their own, unique environment or ‘performance space.’  These environments provide changes to the timbre, or sound quality of sound sources, as well as provide the sound sources (and their musical materials) with additional spatial dimensions. (Blaukopf.  1971. p.170)
    Environments have their own sound qualities that fuse with the timbre of the original instrument/voice to create a new timbre.  This new timbre may be subtly different from the source without the environment, or substantially transformed.  The sound quality of an environment is the result of the spacing in time and the dynamic levels of reflections and by frequency areas or specific frequencies that are accentuated or attenuated by the environment, when a source is sounded.  The proportion of direct sound (unaltered by the environment) to the sounding of the source in the environment (reflections and their characteristic frequency response) will determine the extent the sound source will be altered by the environment.
    In this way, as the sound qualities of environments fuse with the timbre of the instrument/voice, they become part of the spectrum (frequency content) of the instrument/voice, and become incorporated into the timbral balance of overall texture (Moylan. 2007. pp.195-201).  The time elements of environment qualities provide the instrument or voice with added spatial character, as they represent the geometry of the host environment of the sound source.
    The perceived geometry or the ‘illusion of physical dimensions’ of sound source environments contributes to the sound quality and adds spatial characteristics.  This allows environments the potential to generate ambiance for the sound source and to use the ambient sound to (1) provide color alterations to the instrument or voice (Everett. 2009. pp. 339-346) or to (2) extend size of the sound source image (Zak. 2001. pp 76-77).
    Table 6 is an initial summary for how music is transformed or enhanced by environments.



Table 6.  Environment sound qualities and dimensions in music.

5.  Exploring Spatial Qualities of the Overall Sound

    The overall texture of the recorded music has a number of dimensions; among these are the spatial aspects of the perceived performance environment and the sound stage.  These dimensions will (1) provide a context for the music, and  (2) establish a point of reference against which the activities and states of individual sources are measured and understood.

5.1    Perceived performance environment

    The perceived performance environment is the space within which the song takes place.  Its size is the geometry or dimensions of the ‘space’ of the song, and is conceived as a combination of cues from all sources and any applied characteristics. It is static, or unchanging in its dimensions, although its dimensions may gradually show themselves as the song unfolds.  This concept can shape the music in meaningful ways.  To understand how, we can begin my considering:

•    How is the concept of the song reflected in the size of the song’s ‘space’?
•    Is the song bigger than its space? Compatible with? Smaller than?
•    Is the song enhanced by its perceived performance environment?  In what way?

5.2    Sound stage

    As we learned above, the boundaries of the sound stage (L-R width, front-rear distance) are fluid, and have the potential to change as the work unfolds.  Returning to the two versions of “While My Guitar Gently Weeps,” we can recognize that a change in the width and depth of the sound stage occurred in the LOVE version as the Introduction, Verse 1 and first Chorus unfolded.  The White Album version used the sound stage differently: the sound stage boundaries were established at the very beginning, and created a context within which all of the entering instruments and voices were placed and established their locations.
    In considering the sound stage and its relationship to the musical materials, the following Table 7 could serve as an initial point of departure:

Table 7.  Considerations of musical materials and their space qualities, as conceived within the sound stage.

6.  Surround Sound’s Sound Stage

    Thus far we have been examining spatial qualities and relationships of two-channel, stereo recordings.  With surround sound, there are a number of important potential states that are very different from stereo recordings.  
    While all but one of the spatial dimensions discussed above remain conceptually unchanged, how they relate to the listener—and to the listener’s location—can be markedly different.  The medium surrounds the listener with the sound of the music.  This provides a very different experience, with greater flexibility and potentially greater emphasis on the spatial qualities of the music.  
    The overall spatial dimensions of the perceived performance environment and the sound stage remain constant from stereo.  The difference being that the sound stage has the potential to wrap around the listener.
    The spatial dimensions at the individual sound source level remain the same for distance location and lateral location and image size, with the potential change that sound sources have the potential to be placed anywhere around the listener.  Environments of individual sources (or groups of sources) has the potential to exist in a very different and unique manner in surround: the fusion of the direct sound with the reverberant sound that always occurs in stereo (and in our real-world experiences) may be altered in surround to place the two entities in different locations (Holman. 2008. p.135), providing a very different experience.

6.1     Distance in surround

    In surround sound, the listener’s relationship to the sound stage continues to establish a relationship to the music and its communications (expressions/emotions and meanings).  The listener is placed at some distance from the concepts: perhaps intimately close (by very near sound sources of significance), perhaps at a considerable distance.  The relationship of the reverberant energy to the listener, and the use of the rear channels can bring the listener to be observing the performance (recording) within an environment they are experiencing but not necessarily occupying, within an environment they occupy, or even by being seated within the ensemble and its sound stage (especially when instruments are located behind the listener and the rear sides).
    The distance location of the listener relative to the sound stage can extend from being largely detached from the sound stage, to being very close to the front of the sound stage.  These are the same as stereo recordings.  What is strikingly different about surround is that the listener might be placed within the sound stage, which will provide a very different presentation of the music to the listener.

6.2    Location in surround

    Location in surround continues to include the size and lateral location of images, with the concepts discussed above.  Obviously, with surround sound the size of the sound stage can be extended considerably, as the boundaries can be pushed to surround the listener, and the size of images can also be extended (conceptually, though difficult in practice) 360° around the listener.  How the size of the images and locations of the images interrelate with the associated size and locations of the musical materials presented above factor equally in surround.
    The separation of sound sources (and their musical materials) and their host environments is potentially important.  The location and size of ambiance/environment sound can significantly transform the significance, prominence, character and/or sound qualities of sound sources and their musical ideas.  This must be factored into an examination of how spatial properties enhance, transform or present music.

6.3    Surround sound stage in practice

    Figures 5 through 10 provide illustrations of the changing sound stage for the surround sound mix of “While My Guitar Gently Weeps” from LOVE.  Listening to the music recording on an accurate surround sound system will provide an experience substantially different from the two-channel, stereo version discussed above.  The musical parts are spaced further apart in the surround mix, and given more room and less competition—and in some ways less connection to one another.  The dimensions of the sound stage evolve as the music progresses, with the listener gradually becoming more and more immersed in the music of the song, as they are brought further and further within the sound stage and the sound sources/musical materials; still, the sound stage does not fully envelope the listener with instruments or voices from the rear, and a certain degree of observation (and detachment) is maintained.  Differences in distance locations and lateral locations and image sizes are also evident.


Figure 5.  Surround Sound mix of “While My Guitar Gently Weeps” from The Beatles’ LOVE, measures 1 – 8.

Figure 6.  Surround Sound mix of “While My Guitar Gently Weeps” from The Beatles’ LOVE, measures 9 – 24.

Figure 7.  Surround Sound mix of “While My Guitar Gently Weeps” from The Beatles’ LOVE, measures 25 – 40.

Figure 8.  Surround Sound mix of “While My Guitar Gently Weeps” from The Beatles’ LOVE, measures 41 – 48.

Figure 9.  Surround Sound mix of “While My Guitar Gently Weeps” from The Beatles’ LOVE, measures 49 – 56.

Figure 10.  Surround Sound mix of “While My Guitar Gently Weeps” from The Beatles’ LOVE, measures 57 – 72.

    How are these spatial differences between the stereo and surround mixes significant musically?  Do these changes in spatial quality communicate something different (change of the concept of the song or its meaning or its substance)?  Do these changes in spatial quality bring the materials and their presentations to merely communicate the same substance differently (change the quality of the material as ornamentation, but not alter its substance)?

7.  In Closing

    This is a beginning to seek a greater understanding, and not intended to offer an overview of practice, or a theory of principles.  It has been offered to establish a framework and to start a context for inquiry and for discovery of how space functions in recorded music.
    Spatial Qualities of recordings are potentially striking, and their sonic significance is undeniable.  These spatial qualities can become an integral part of the composition or add important characteristics of many types.  They can:

•    Transform musical materials and relationships;
•    Provide added dimensions to instruments and voices;
•    Enhance the overall musicality of the recording;
•    Give added meaning and character to a song’s musical parts;
•    Contribute to a convincing presentation of the song;
•    Enliven and enhance the delivery of the message or the emotive expression the song/music is communicating;
•    Add substantive musical material to the song;
•    Provide a context or point of reference for the recording/music,
•    And much more.

    The underlying questions remain:  How do we define the activities and states of spatial qualities as musical materials (concepts) or as ornamental embellishments within the musical texture?  How do we calculate their impact on the music, their functions and significance?

References and Bibliography

Blaukopf, Kurt. 1971. “Space in Electronic Music,” Music and Technology.  New York. Unipub.
Chowning, John.  1977.  “The Simulation of Moving Sound Sources,” Computer Music Journal, Vol. 1, no. 3 (June 1977).  Pp. 48-52.
Everett, Walter.  2009.  The Foundations of Rock: from Blue Suede Shoes to Suite Judy Blue Eyes.  Oxford.  Oxford University Press.
Hertsgaard, Mark.  1995.  A Day in the Life: the music and artistry of the Beatles.  New York.  Delacorte Press.
Holman, Tomlinson.  2008.  Surround Sound: up and running, second edition.  Boston.  Focal Press.
Moorefield, Virgil.  2005.  The Producer as Composer: shaping the sounds of popular music.  Cambridge, MA.  The MIT Press.
Moylan, William.  2007.  Understanding and Crafting the Mix: the art of recording.  Boston.  Focal Press.
Moylan, William.  1992.  The Art of Recording: the creative resources of music production and audio.  New York.  Van Nostrand Reinhold.
Moylan, William.  1986.  “The Aural Analysis of the Spatial Relationships of Sound Sources as Found in Two-Channel Common Practice.”  Paper presented to the 81st Convention of the Audio Engineering Society, November 1986.  Los Angeles.
Tenney, James.  1986.  Meta – Hodos and META Meta – Hodos.  Oakland, CA.  Frog Peak Music.
Zak III, Albin J.  The Poetics of Rock: cutting tracks, making records.  Berkeley.  University of California Press.

Discography

Beatles, The.  1968.  “While My Guitar Gently Weeps” on The Beatles (the ‘White Album’).  Capitol.
Beatles, The.  2006.  “While My Guitar Gently Weeps” on LOVE. Capitol. (CD)
Beatles, The.  2006.  “While My Guitar Gently Weeps” on LOVE. Capitol. (DVD-A)
Pink Floyd.   2003.  “Money” on Dark Side of the Moon.  Capitol.