An important, time-honored way to increase the energy of music is by speeding up. Of course, speeding up the tempo, the speed of the beat, is a very familiar means of doing so. I want to explore a larger concept here, horizontal density, which refers to the number of events per unit of time. Events might be anything, whether notes in a scale, a note repeated over and over, a particular sound, a very high or low sound or note: anything that is similar enough to be perceived as repeating.
Composers over the centuries, modern rock bands, musical cultures around the world all make use of horizontal density to alter the energy of the music created. Whether and how horizontal density is altered in music is an aspect of style that helps us recognize a band, a composer, a musical period, culture or subculture.
Examples one can hear provide the best way to understand this concept, so let’s examine some. Here comes a series of listening experiences culminating in a brief analysis of the energy transformation in a jam by the Grateful Dead.
In the first pair of examples below, I’m using a descending scale, first with a slow pace of notes, then with a faster pace. Observe that the faster succession of notes produces higher level of energy.
Example 1: Scale down, slow
Example 2: Scale down, fast
Using the same scale down, now listen to the impact on energy of slowing down while descending.
Example 3: Scale down, slowing
Compare that to the energy change of a scale down accelerating. Here, there are two versions of accelerating, one in which the acceleration is continuous over time, and one in which the beat audibly speeds up (listen a few times if you don’t notice that right away!)
Example 4: Scale down, speeding up
Example 5: Scale down, speeding up the beat
And at last, an excerpt of real music! Here is an improvisation during a performance of Morning Dew by the Grateful Dead that demonstrates the way increases of horizontal density gradually build energy over time. The annotations found below the example trace the appearance of higher-density passages in the solo guitar that get picked up by others.
Example 6: Morning Dew, Grateful Dead live at Winterland, 1974.02.24 (50 years to the day before this blog post was completed and published!)
The excerpt begins with quite low horizontal density. Little flurries of higher density (that is, faster notes) come from Jerry Garcia’s lead, and the increased horizontal density spreads subtly to others in small waves. At about 1:05, the whole band is picking up the density, especially of louder sounds, and beginning to fill in around Jerry’s solo with little waves of faster notes. By 1:50 and beyond, Jerry really gets going, with faster notes coming in waves after stronger articulations. At 2:25, Bob Weir (“rhythm” guitar) picks up Jerry’s faster chords and really builds energy with rapid repetitions. At the very end of this excerpt, both guitars briefly thrash chords rapidly together, marking a major arrival of energy in the jam.
You probably notice additional factors that increase the energy in conjunction with horizontal density: among other things, the music grows gradually louder and higher as well as featuring faster notes. It is this combination of energy increases, acting rather in counterpoint to each other, bringing along the overall energy bit-by-bit, that demonstrates the Sound-Energy Aggregate in action.
Using the interaction of musical parameters to control musical energy is a global phenomenon with ancient roots. Reckoning their impact on the overall energy flow is the basis of an analytical method that can deal with music from any culture. Look for more demonstrations of that reality in this blog.
Thank you, John! I enjoyed this. I learned a new term today!