Descriptors of Acoustical Energy

As musicians, we consciously use sound as a form of expression. The exercises and related videos below dive into the physical properties of sound. The information is basic and designed to serve a younger audience looking to better themselves through intonation practice. Although the examples are done with the horn, they can be practiced with any instrument.

Before jumping to the exercises, be sure to print out the intonation tendencies reference. It will serve as a great tool for all of the exercises here.


Descriptors of Acoustical Energy

Droning exercises necessitate a perceptual approach to learning. The videos presented on this page will cover perceptual reasoning and proper relative pitch development through the use of a drone – a constant, reliable pitch to play and analyze against.

A student, new to the drone, does not necessarily know where to begin their journey to improve their intonation. There are two things that tend to go wrong without proper coaching.

  1. Because the horn is a transposing instrument, confusion between the pitch to drone and the pitch to played on the horn is common. If the student is looking at a horn part, the instrument will sound down a perfect fifth. If a student sees a second line G on the horn part, it will sound a C below. If using an analog tuner, be aware of the horn pitch and concert pitch differentiation. If using a digital tuner (like Tonal Energy), lock the drone into horn transposition F +5.
  2. Make sure the drone is loud enough to encourage the student to play out. If they play with a weak, feeble tone, quality intonation will not be reached.

As an educator, one of the best pieces of advice I can offer is something that was told to me by the former principal horn of the Cleveland Orchestra, Richard King — Always-Sound-Beautiful.

We, humans, describe sound using four different categories: waveform, frequency, amplitude, and time. There are five videos below. The first is an introduction, the other four concentrate on each descriptor of acoustical energy.

I strongly urge you to download and use the Tonal Energy app for these exercises. It is reliable, easy to use, and fun!


This video acts as an introduction to the material presented on this page. Be sure to download the Tonal Energy app before viewing!

Video: Intonation and Droning


Video: Waveform and Timbre


The descriptors of acoustical energy videos begin with a video concentrating on the concept of the waveform. How sound travels is a fascinating subject and I bring it to my audience by keeping things simple – play a consistent, high-quality note. We perceive waveform as timbre. It is very important for a young player to understand that musical instruments produce a sound that contains several types of sounds within. These are called harmonics.

The horn can produce a very attractive sound quality due to the type of resultant wave produced. The resultant wave of any instrument consists of the fundamental pitch played as well as the harmonics associated with that instrument. For instance, the image below represents an instrument playing a fundamental tone (red) and its first two harmonics – the first harmonic (purple) has twice as many waves as the fundamental and the second harmonic (blue) has three times as many waves as the fundamental. Students may not realize that the three waves come together (naturally and mathematically) to form a resultant wave (green). It is the resultant wave that carries the timbre (quality of sound) to the listener:

resultant wave.png

The image below represents a consistent resultant wave of a horn as it is represented on an oscilloscope. The timbre of the horn is represented by this waveform.

horn tone

The exercise developed for this video is called PERFECT UNISON DRONING. It is a simple exercise focused on creating a beautiful sound quality while maintaining a consistent pitch with the drone.


Video: Frequency and Pitch


The purpose of the third video (waveform) is to learn to play a consistent, steady pitch with a drone playing the unison at the same time. I avoid talking about articulation in order to allow the student to concentrate on creating a beautiful tone quality. The second descriptor of acoustical energy presented has to do with frequency. Pitch is entirely dependent on frequency. Frequency is the measurement of the number of periodic waves that pass a given time span. We quantify this measurement as pitch. Below is a descriptive frequency image. The higher number of waves in a given span of time (purple), the higher the pitch. The lower number of waves in a given span of time (red), the lower the pitch.

frequency pic

An exercise titled, PERFECT 4TH / 5TH DRONING is an adaptation of a method created by Carmine Caruso and championed by Julie Landsman. The video focuses on the use of the perfect-5th as a tool to help keep pitch down. The perfect-5th is naturally a wide interval. By having the drone play a fixed pitch and having the player produce a note a perfect-5th below, the player would need to adjust their pitch downward. It is not a large adjustment but it is an adjustment necessary to learn. If made part of a consistent practice regimen, the player will find themselves inherently adjusting faster and paying more attention to the tonal quality of the “hallow” sounding perfect-5th.


Video: Amplitude and Loudness


The third descriptor of acoustical energy displayed by this project is amplitude. Amplitude is the measurement of how much energy is contained within a sound wave. Measuring and describing this type of energy is generally done using the decibel (dB) scale. The human perception of amplitude is displayed by loudness. Two pitches can have the same peaks and valleys in their waveform but if one has greater peaks and valleys (bottom bird) the sound can resonate the same frequency but at a higher volume.

amplitude bird

Although students have a greater awareness of this concept, I find that very few young students are unaware of how dramatically their sound changes when playing from soft to loud and when playing from loud to soft. I adapted a long tone exercise, written by Douglas Hill, for the use of this video. The exercise necessitates both very loud playing and very soft playing. When playing loud it is very easy for a student to unknowingly meander (or sometimes sprint!) sharp – this is caused by the inability of the aperture to control the vast amount of air it is bombarded with. The player would need to make a conscious effort to mentally engage with the aperture and their ear to properly place the pitch where required.


Video: Time and the Sound Envelope


The fourth descriptor of acoustical energy discussed in this project is time and the sound envelope. Sound is a temporarily based phenomenon. The addition of the drone to this exercise allows the student to focus on the beginning, middle, and end of the note being played. Time can be measured in absolute units. The Sound Envelope encompasses the changes that occur over the course of a single sound — a tone (or group of tones). The sound envelope below is a representation of a note played over time. The sound envelope consists of four distinct parts:

  1. attack — the front of the note.
  2. decay — the development of timbre and definition of note center.
  3. sustain — the length of the core of the note
  4. release — the ending of the note.

The exercise adapted for this video is called TAPERED DRONING. The germination of this tune began with the Pre Warm-Up, found in The Art of French Horn Playing written by Philip Farkas. I adapted the exercise to use the analysis feature offered by the Tonal Energy App. Using this feature will allow the player to see how their sound develops over time.