Brian K. Shepard Learning Objects Site Menu
The creation of interactive learning objects for music students has been another important focus of my energy and research. My idea is to create easy-to-use and single-focus learning objects that students can run in a lab, or on their own computers, that teach or reinforce concepts from a variety of music courses. Because of the flexibility afforded with the free runtime application, these objects are all created in Max from Cycling '74. Students don't need any special hardware in order to use these objects, just the free Max Runtime application, available for both Macintosh and Windows computers and some headphones or speakers. Feel free to use and distribute these learning objects as you see fit. I only ask that you don't remove the copyright information from the objects. If you would like to explore creating your own objects, you might be interested in the presentation I made on Creating Interactive Learning Objects (pdf) to the Association for Technology in Music Instruction (ATMI) annual conference in 2009.

Get Max 6.x Runtime (It's free and it's required to use the learning objects.)
If you experience difficulties getting the learning objects to play through your audio interface, use the Audio Driver Configuration (125KB) tool to set Max Runtime for your interface.
Audio Driver Configuration
Users of Pro Tools (or other Avid products) may find that Pro Tools--not Max Runtime--attempts to launch when double-clicking these learning objects. If so, change the "Open with..." setting for the .mxf file type to Max Runtime and select "Change All."

Download the entire set of learning objects (51.3MB), or select the individual objects below.

Sound Basics (download 271KB)
Students often confuse some of the basics of sound and audio terminology like frequency and amplitude. This simple demonstration makes the difference abundantly clear as it illustrates three basic components of sound: Frequency, Amplitude, and Wave Length. Students can adjust the frequency and the amplitude as they both see and hear the result. As they adjust the frequency, the wavelength is automatically calculated for them.

Sound Basics Learning Object
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Equal Loudness (download 338KB)
This demonstration helps students understand that our hearing is not linear. They are first presented with two tones, one at 100Hz and another at 2kHz. They use the up/down arrow keys on their computer to adjust the loudness of the 2kHz tone until it sounds at the same loudness to them as the 100Hz tone. Once they have done that, they click the "Reveal" button to see the actual signal level for the two tones after their adjustments. They can then try the same experiment with a 10kHz tone compared to a 100Hz tone. This demonstration is best used in conjunction with the Equal Loudness contours to help the students understand that our perception of loudness varies depending on frequency.

Equal Loudness Demonstration
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Oscillator Wave Types (download 218KB)
The Oscillator Wave Types demonstration allows the student to easily compare the sonic qualities of the four basic wave types—sine, triangle, sawtooth, and square—all at the same frequency. They can change the base frequency by either clicking-and-dragging the frequency box, or by playing notes on a MIDI keyboard.

Sound Wave Types
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Combining Sound Waves (download 366KB)
Nearly every semester I have a student who asks something like, "If we only have one eardrum in each ear, how do we hear all those different sound waves?" This demonstration helps students understand the concept of additive wave energy. They start by looking at and listening to a single sound wave, and add another to it while they both hear and see the combined result. Then they add a third wave and the concept begins to crystallize. The "What Have We Learned?" button opens a second window that explains the concept of sound wave interactions.

Sound Wave Interactions
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Phase Cancellation (download 228KB)
This demonstration follows up on the concepts learned in the previous Combining Sound Waves demonstration. In this case, the student is presented with two identical sine waves that are perfectly in phase. They note that the amplitude of the sum of the two waves is exactly twice that of each of the individual waves. As they move the "Phase Slider," the second wave is moved out of phase until it reaches 180º—completely out of phase. At that point, the student will see that the two waves completely cancel each other out.

Phase Cancellation Demonstration
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Beat Frequencies (download 266KB)
This demonstration is another follow-on to the earlier Combining Sound Waves demonstration. In this case, the concept of “Beat” frequencies is both shown and heard. The students combine two sound waves of the same type and amplitude, but slightly separated in frequency. As the two waves go in an out of phase with each other, they are able to hear and calculate the “beats” that occur.

Beat Frequency Demonstration
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Beat and Sideband Frequencies (download 496KB)
This is a follow-up to the earlier Beat Frequencies demonstration, and extends the concept of beat frequencies into their audio-rate equivalent: sideband frequencies. The demonstration allows students to hear the beat and sideband frequencies that occur when two waves sound together. They can begin with one of the four presets and isolate the various real and sideband frequencies by clicking the buttons to solo them. When they have finished with the presets, they can create their own beat and sideband frequencies by changing the frequencies of the two oscillators.

Beat and Sideband Frequencies
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Harmonics (download 335KB)
Music students hear about harmonics all the time, but few of them actually understand what they are, and the importance they bear on the tone quality of a sound. This demonstration allows students to combine harmonics—up to the 16th harmonic—as they both see and hear the results. A menu of presets gets them started, but they are free to create their own spectrum of harmonics.

Harmonics Demonstration
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Just Intonation (download 13.5MB)
Music students are taught that the Well-Tempered and Equal-Tempered Intonation systems were a major "improvement" on the Just Intonation system, and that it now allows musicians to play in all chromatic keys. However, most never really get to experience the difference. This object demonstrates the differences between Just Intonation and Equal-Tempered Intonation on three different levels. First they listen to different intervals as they quickly switch back and forth between the two temperaments. Then, they listen to common chord types in both temperaments. Finally, they listen to a short Bach chorale excerpt in both Equal Temperament and Just Intonation, but in two different keys. Playing the chorale in the "wrong" Just Intonation tuning is a real eye-opener for them.

Just Intonation Demonstration
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Tone Row Matrix Generator (download 399KB)
This demonstration creates randomly generated tone rows and illustrates the standard matrix system used by serial composers. The students tell the application how many notes they want in the row and the application generates the matrix. Clicking the four “Play” buttons plays the row in one of its standard permutations: Prime, Inversion, Retrograde, and Retrograde Inversion.

Random Tone Row Matrix Generator
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Additive Synthesis I (download 418KB)
This demonstration illustrates one of the basic concepts of synthesis, additive synthesis. Students can combine as many as six oscillators at different frequency ratios to create a complex tone. There is a list of presets to get them started, but they are free to modify them as desired. They can then use that tone to play melodic passages or chords on either an external MIDI keyboard, or by clicking the on-screen keyboard.

Additive Synthesis Demonstration
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Additive Synthesis II (download 631KB)
A follow-up to the earlier Additive Synthesis I demonstration, this object allows students to create all kinds of interesting and exotic sounds by combining up to 16 harmonics and partials at different ratios and amplitudes. All of the sounds created in this demonstration are done entirely by adding sine waves together. A menu of presets gets the student started, but they are free to experiment with their own combinations as they both see and hear the result. They will also learn that all four of the basic waveforms (sine, sawtooth, square, and triangle) can be created with additive synthesis.

Additive Synthesis II
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Subtractive Synthesis (download 492KB)
This demonstration illustrates another of the basic concepts of synthesis, subtractive synthesis. Students begin with a complex sound rich in harmonics and partials as they selectively apply audio filters to adjust the timbre of the sound. There is a list of presets to get them started, but they are free to modify them as desired. They can then use that tone to play melodic passages or chords on either an external MIDI keyboard, or by clicking the on-screen keyboard.

Subtractive Synthesis Demonstration
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Oscillator Sync (download 496KB)
Oscillator sync is found on numerous “analog” synthesizers, but is generally not well understood by most users. This demonstration illustrates, both audibly and visually, what happens when a “master” oscillator forces a “slave” oscillator to restart its wave every time the master oscillator starts its wave. The result is the pitch of the master oscillator, but with some interesting sideband frequencies as a result of the synced slave oscillator. Students are able to isolate the two oscillators, and then combine them to hear and see the result.

Oscillator Sync Demonstration
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Ring Modulation (download 411KB)
Although ring modulation is technically a form of amplitude modulation, it is often found as an effect on synthesizers rather than as a sound source. Ring modulation multiplies two frequencies by each other, only outputting the sum of the two frequencies and the difference of the two frequencies. It is commonly used with one of the sounds, the carrier, being a steady tone while the other sound, the modulator, is a complex, changing sound. This demonstration allows students to ring modulate a synthesized sound, a pre-recorded speech audio file, and even their own microphone’s input.

Ring Modulation Demonstration
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FM Synthesis (download 403KB)
The complexities of FM (Frequency Modulation) synthesis are broken down to their basic components in this demonstration. Students can experiment with different ratios between the modulator and the carrier oscillators, as well as experience the effect of changing the amplitude of the modulator oscillator. A number of presets provide some good starting points, but students are free to create their own sounds by adjusting the harmonicity ratio and modulator amplitude as they play notes on their keyboard.

FM Synthesis Demonstration
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Audio Filter Types (download 7.28MB)
This demonstration allows students to take a variety of sound sources and types (synthesized sound, white noise, and music) and apply a number of different audio filters to the sound (lowpass, highpass, bandpass, bandreject, parametric, lowshelf, hishelf, and allpass), as they manipulate the center/cutoff frequency, filter amplitude, and "Q" or Resonance. As they select a filter, a description of the filter appears next to the selection drop-down menu.

Filter Demonstration
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Audio Filter Controls (download 682KB)
One of the frequently confusing aspects of using an audio filter is the fact that the functions of the controls often change depending on the type of filter being used. This usually happens as a result of the GUI designer's desire to save space on the interface. In this demonstration, as the filter type changes, so does the actual name of the control so that it accurately reflects the control's function. Users are also provided a description of the control function as the move the mouse over each control knob.

Audio Filter Controls
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Audio Filter Modulation (download 631KB)
After exploring Audio Filter Types in the previous demonstration, students then focus on filter modulation with this demonstration. Here they apply a number of modulators like keytracking, velocity, aftertouch, and modulation wheel to the resonance and cutoff frequency of a lowpass filter to modulate the filter in real time as they play on their keyboard.

Filter Modulation Demonstration
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The Color of Noise (download 246KB)
Noise is an interesting concept to most students who have never thought of it in the acoustic or music sense. This little demonstration allows them to hear noise in its basic colors: White, Red, Pink, Violet, and Blue. To help them remember the color/sound combination, the sonogram changes color with each noise "color."

The Color of Noise
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Wavetable Oscillator (download 465KB)
As students of synthesis quickly learn, additive synthesis is incredibly computationally expensive. Most synthesizers get around this problem by using wavetable oscillators to mathematical create a single cycle of a complex waveform. This demonstration allows students to create their own waves by adjusting the amplitudes of the first eight harmonics of a wave while they both see and hear the results. Playing different notes on MIDI keyboard changes the fundamental pitch of the wavetable oscillator.

Wavetable Oscillator
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Grain Source (download 17.1MB)
It can be difficult to hear what is happening to each grain in granular synthesis. This demonstration allows the student to isolate the grains in the granular “cloud” by setting large interval values for the Grain Density Range (between 700-1000ms). That moves the grains far enough apart that they can hear and understand the individual manipulations that occur within the grain source of a granular synthesizer.

Grain Source
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Shaping Sounds with an Amplitude Envelope Generator (download 463KB)
The amplitude envelope generator is a basic function of any synthesizer and allows the user to shape the oscillator sounds so that they have a beginning, a middle, and an end. Amplitude envelope generators create the articulation of a sound. Students can use this demonstration to experiment with different envelope shapes and to hear the articulations that different envelope shapes create.

Amplitude Envelope Generator
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Multi-Stage Envelope Generators and Additive Synthesis (download 415KB)
Multi-stage envelope generators provide more breakpoints than the standard ADSR envelope generator. Those additional stages can be extremely useful when shaping a sound, or as in this case, when combining sounds with additive synthesis. In this demonstration, all of the complex sounds are created by combining triangle-wave oscillators at six different harmonic and inharmonic ratios. By applying different multi-stage envelopes to the individual oscillators, that complex sound is shaped into one that evolves over time.

Multi-Stage Envelope Generators
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Envelope Generator Behavior Modes (download 631KB)
On more sophisticated synthesizers, envelope generators are not static. They change based on a variety of different inputs and playing techniques. This, and the next, demonstration illustrate the most common ways an envelope generator may be programmed to behave. In this object, the envelope generator responds to different note lengths and changes its response based on whether a phrase is played legato or staccato. Students can see and hear exactly how the envelope generator behaves under each of these different modes.

Envelope Generator Behavior Modes
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Dynamic Amplitude Envelope Generator (download 361KB)
Most contemporary synthesizers allow users to modulate both the amplitudes and times of the amplitude envelope generator based on key velocity and key tracking. This demonstration allows students to try each of these parameters individually as well as collectively, as they both see and hear the envelope's dynamic response.

Dynamic Amplitude Envelope Generator
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Tempo to LFO Rate Calculator (download 212KB)
If your synthesizer does not synchronize to note values, use this handy little calculator to find the appropriate LFO rate based on tempo and desired note duration.

Tempo to LFO Rate Calculator
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Low Frequency Oscillators (download 456KB)
Low Frequency Oscillators, or LFOs as they are usually called, are some of the most popular and important modulators found on a synthesizer. This demonstration allows you to use a low frequency oscillator in three of the most common LFO applications by assigning it to modulate either the amplitude or frequency of an oscillator or the cutoff frequency of a resonant lowpass filter. Try the different LFO shapes as well as adjusting the depth of the modulation effect and the rate and phase of the LFO wave.

Low Frequency Oscillators
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Audio-Rate Oscillators (download 564KB)
Audio-Rate Oscillators function much like the Modulator in AM and FM Synthesis, except instead of modulating the amplitude or frequency of an oscillator, they modulate some other aspect of the synthesis process. By far, the most common use of audio-rate oscillators is to modulate the cutoff/center frequency of an audio filter. This demonstration lets you use an audio-rate oscillator to control the cutoff frequency of a resonant lowpass filter. For comparison, you can also change it to actual FM Synthesis to hear the difference between modulating the cutoff frequency of a filter and modulating the frequency of an oscillator.

Audio-Rate Oscillators
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Function Modulator (download 294KB)
Function modulators take the outputs of two or more control signals as inputs and apply a mathematical formula to them, creating a new modulator signal. This demonstration applies a variety of formulae to the outputs of a Modulation Wheel controller (a) and a 0.5Hz sawtooth LFO (b) to modulate the pitch of an oscillator. As the Depth slider is increased, the amount of the modulation effect on the oscillator's pitch is heightened. The last two formulae feed the output of the Function Modulator formula (y) back into itself to create a more random result.

Function Modulator
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16-Step Sequencer (download 691KB)
Step sequencers are used to create rhythmic patterns from synthesizers sounds. In this demonstration, you can control the pitch and velocity of the oscillators sounds as well as the cutoff frequency of a resonant lowpass filter. Sustain a note or chord and start the sequence.

16-Step Sequencer
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Creative Commons License
These Music Interactive Learning Objects by Brian K. Shepard are licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at briankshepard.com.
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