and a retrieval failure. Sometimes using different retrieval cues can bring up
memories that seemed previously unreachable. Current memory researchers
use a variety of different methods to study remembering, forgetting, storage,
and retrieval processes.
13.3 Working Memory Capacity
George Miller (1956) pointed out that working memory has a limited capacity.
The number of pieces of information we can juggle in short-term memory at
any one time is between 5 and 9, or what he called ‘‘7G2.’’ As a demonstration,
try to keep the following series of digits active in memory:
015514804707619
Most people can’t keep this many (15) going at once. It is indeed a bit like
juggling. But try again, by looking at the numbers when they are rearranged
from right to left, as below:
916707408415510
If you’re from California, you’ll notice that these are the telephone area codes
for the northern part of the state. If these are familiar to you, they become
grouped—or ‘‘chunked,’’ to use Miller’s word—and voila`!—suddenly there are
only five pieces of information to remember and it is possible to keep them
active in working memory. As another example, consider the following string
of fifteen letters:
FBICIAUSAATTIBMIf you are able to chunk this into the familiar three-letter abbreviations, the
problem is reduced to keeping five chunks in memory, something most people
can do easily.
What does chunking have to do with music? People who study ear-training
and learn how to transcribe music are probably chunking information. For ex-
ample, in a typical ear-training assignment, the instructor might play a record-
ing of a four-piece combo: piano, bass, drums, and voice. The student’s task is
to write down, in real time, the chord changes, bass line, and melody. If you
have never done this before, it seems impossible. But with chunking, the prob-
lem becomes more tractable. Although the chords on the piano each consist of
three, four, five, or more notes, we tend to hear the chord as a chord, not as
individual notes. Beyond this, musicians tend to hear not individual chords but
chord progressions, or fragments of progressions, such as ii-V-I or I-vi-ii-V.
This is analogous to seeing FBI as a chunk and not three individual letters. The
chord changes can be parsed this way, and if the listener misses something, the
part that is there provides constraints the listener can use to make an educated
guess about the part that is missing. You can see the role of contextual con-
straints in reading. It is not hard to guess what the words below are, even
though each is missing a letter:
basso_n cof_eeMemory for Musical Attributes 297