This doesn’t necessarily mean the perceptual details are lost: the child may
maintain a vivid image of the exact car; but the conceptual system of the
brain, along with the memory system, by necessity must integrate details into
generalizations. In fact, there is a great deal of evidence that memory does
preserve both the details and the ‘‘gist’’ of experiences, and we are usually able
to access information at the appropriate level.
13.5 Memory for Music
Objects in the visual world have six perceptual attributes: size, color, location,
orientation, luminance, and shape. What do we mean by ‘‘object’’? This defini-
tion has been the subject of heated argument among theorists for many years. I
propose that an object is something that maintains its identity across changes
(or transformations) in these attributes. In other words, as we move an object
throughspace,itisstillthesameobject.Ifyouweretochangethecolorofyour
car, it will still be your car. Shape is a tricky attribute, because shape distortions
can sometimes, but not always, alter an object’s identity. For example, as was
shown by William Labov (1973), a cup becomes a bowl if the ratio of its diam-
eter to its height becomes too distorted.
A performance of music contains the following seven perceptual attributes:
pitch, rhythm, tempo, contour, timbre, loudness, and spatial location (one might
add reverberant environment as an eighth). Technically speaking, pitch and
loudness are psychological constructs that relate to the physical properties of
frequency and amplitude. The termcontourrefers to the shape of a melody when
musical interval size is ignored, and only the pattern of ‘‘up’’ and ‘‘down’’ mo-
tion is considered. Each one of these eight attributes can be changed without
changing the others. With the exception of contour, and sometimes rhythm, the
recognizability of the melody is maintained when each of these attributes is
changed. In fact, for many melodies, even the rhythm can be changed to some
degree and the melody will still be recognizable (White 1960).
To elaborate further, a melody is an auditory object that maintains its identity
under certain transformations, just as a chair maintains its identity under certain
transformations, such as being moved to the other side of the room or being
turned upside down. A melody can generally retain its identity with trans-
formations along the six dimensions of pitch, tempo, timbre, loudness, spatial
location, and reverberant environment; sometimes with changes in rhythm; but
rarely with changes in contour. So, for example, if you hear a song played louder
than you’re accustomed to, you can still identify it. If you hear it at a different
tempo, played on a different instrument, or coming from a different location in
space, it is still the same melody. Of course, extreme changes in any of these
dimensions will render the song unrecognizable; a tempo of one beat per day,
or a loudness of 200 dB SPL might stretch the limits of identification.
A specific case of transformation invariance for melodies concerns pitch. The
identity of a melody is independent of the actual pitches of the tones played.
A melody is defined by the pattern of tones, or the relation of pitches to each
other. Thus, when we transpose a melody, it is still recognizable as the same
melody. In fact, many melodies do not have a ‘‘correct’’ pitch, they just float
Memory for Musical Attributes 299