Electronic Musical Instrument Design

lecture notes • Spring, 2017

Mar 28

After each lab session:
Put tools away.
Put common parts away. Be courteous to the other teams!
Put power tool batteries in their chargers.
UNPLUG soldering equipment.
Don't leave any files on the Mac Desktops.

Projects are due April 10.
Team evaluations are due April 10 @ 9pm.
Writeups are due April 11 @ 9 pm.

Mar 13

Final Proposals and shopping lists due Wednesday!

Meta-events: events about events. How do you implement them in Max?
Use Objects: metro, tempo, sliders, dials, lists of numbers, random, number boxes with limits and offsets
  Tempo, accelerate & ritard
  Range, also restrict to key, scale, chord
Tendency masks: "clouds" of random numbers controlling function to keep it within certain limits, and changing the limits over time
  Crescendo and diminuendo, using velocity (control over individual notes, but only one velocity byte per event) vs. volume (continuous control of level, affects all notes on that MIDI channel)
  Harmony: distance between notes. Does it follow key, scale, or chord?
  Counterpoint: how musical voices move against each other, parallel, opposing, combination
  Orchestration: use multiple Reason modules on multiple MIDI channels to layer different sounds or create an orchestra.
Density: growing/shrinking chords or clusters using module's polyphony setting
Example: The Sonic Pyramid

Sources of parts:

• basic electronics, huge inventory, complex search engines

• specialized electronics, less inventory, good guidance

• cool miscellaneous electronics

• plastic, acrylic, rubber, nuts and bolts, hardware in general

• buttons!


Events this week!
• Tuesday noon, Granoff 155: Professor Lehrman Colloquium: What Was George Thinking? An examination of some of the technology Antheil might have wanted to use to perform Ballet mécanique. Lunch follows!
• Tuesday 8 pm, Distler Auditorium: Documentary film on the Ballet mécanique score; Lecture on the history of the Ballet mécanique film; performance of "piano concerto" version of Ballet mécanique with the film.
• Wednesday 1:30 pm, EMID lab: guest lecture demo by controllerist Moldover.
• Wednesday 4:30 pm, Granoff 155: guest lecture by Seinfeld composer Jonathan Wolff.
• Friday & Saturday: at Berklee College of Music, "Voltage Connect" conference. https://www.berklee.edu/voltage-connect

Mar 6

Designing an instrument:
What gestures will control it?
What sensors do you need for those gestures?
What will need to be done with the sensors to make them "playable", e.g., mounted on wood, put in tubes, duct-taped to your head?
How do the sensors translate into switch contacts, or 10KΩ resistors, or +5V DC sources, to use with the Arduino? Will there need to be supplementary electronics?
What processes will be applied to the MIDI data coming from the Arduino in Max?
What will the instrument sound like, and how will the sound be controlled by the gestures?

Assigning team tasks:
Specifying and obtaining sensors.
Specifying materials to make sensors playable, i.e., the human interface.
Wiring the sensors making the wiring robust.
Adding circuits to process sensor data.
Writing the Max patch to process the data.
Designing the Reason patch.

Document wiring and circuits!

Signal Processing in Reason
Processing modules: reverb, complex reverb, flanger, delay, scream, etc.
Assign each module a MIDI channel in Reason Hardware Interface.
Controller numbers assigned to each parameter are in the MIDI Implementation Chart PDF or in folder "Reason controllers".
Use Max to assign different incoming data to different channels to control efx, mix, aux sends, panning, etc.

Mar 1

Lab safety and rules: Goggles when using any power tools.
No power tools when you’re alone. Make sure there's someone in the building who knows you're in the lab!
Don’t use tools you don’t know how to use, especially drill, Dremel, soldering irons, jigsaw.
Unplug soldering irons after use. Unplug glue gun after use.
Don’t overuse hot glue. Heat destroys components.
No spray painting in the building: take objects outside and use cardboard backing so paint doesn’t get on pavement or grass.

Reason NN19 module: samples, with many of the same filtering and envelope parameters as Subtractor.
Building sample map: from Reason Library, or drag in from Finder. Automap assigns all incoming samples to their own key zones.
Aligning pitches in sample map—setting root note. Keyboard tracking=no pitch change.
AIFF/WAV/MP3 audio formats. Samples can be mono or stereo.
Record your own samples with computer mic or external.
SFX libraries on all disks.
Self-contain setting

For 3D printer use Onshape. Create your own account—it's free! Export file and open in Cura, then save to SD card and bring to printer.

Feb 23

Wiring and soldering
• Safe use of the soldering iron
• Assembling components on a breadboard and soldering them
• Good soldering practice
• Using heat sinks
• Unsoldering and removing components
• Wiring sensors and other components to the Arduino
• Testing the Arduino digital and analog inputs using the Arduino2Max object
• The different models of Arduinos

Feb 22

Toggle, push-button, momentary, lever, magnetic
Rotary encoder: has two different switch contacts, “0” and “1”. Speed of encoder determined by how fast switch contacts are made; direction determined by order of contacts.
Continuous sensors can act as resistors or current generators. Some, like rotary or slide potentiometers, can be connected directly to the Arduino. Others need buffering, amplification, and/or filtering to provide usable signal.
• Force-sensing resistor=pressure. Button-type or strip.
• “Softpot”, flat variable resistor, ribbon or circular
• Joystick=two-dimensional variable resistor
• Flex sensor=bending angle
• Infrared distance sensor=from about 1.5-10 inches. Available in various ranges. Get too close and the field inverts.
• Photocell: presence or absence of light
• Accelerometer: 1-axis, 2-axis, 3-axis. More sensitive ones can measure tilt (responding to gravity)
• Piezo electric foil=striking or bending force. High voltage.
• Capacitive
• Color and gesture: https://www.sparkfun.com/products/12787
• Myelogram https://www.sparkfun.com/products/13027

Feb 13

Intro to Max: 30-day free trial : http://cycling74.com/downloads/

Check AudioMIDI Setup to see that MPD or keyboard is recognized.
Launch Max. Before opening a patch, check Max's MIDI Setup: in a is MPD or keyboard, out a is "from Max1". Disable all other inputs and outputs

Launch Reason. In Preferences>Sync set Bus A to "from Max1".

Edit and locked mode. command-E toggles, or click on lock icon.

object box = a function
start typing, list of objects appears following your input.

Number box = for monitoring.
Can choose to display MIDI note numbers OR names (get info)

Patch cables connect everything.

notein arguments: port a, note#, velocity, channel
noteout: same

makenote: note#, vel, length. Has to then go to a noteout. test for not-zero [ != 0 ]

cntlin: controller value, controller #, channel (if no channel, will accept all. If wrong channel, won't respond)
cntlout: same

Sliders (0-127), can change (Get Info). Kslider, shows keyboard.

Pipe: number of arguments is number of messages passed, with last one being delay time in ms. "0 0 0 time" will delay a MIDI message (zeroes are placeholders).

Random n=puts out random value 1-n

Metro=clock, number of milliseconds. Start and stop with toggle at input.
Select, waits for value, passes 1.

MIDI Scope patch for monitoring input.

Print command: open Max Console window to view output

Feb 8

Akai MPD26 and Reason
Using MPD with Reason--you can now control anything on the panel with the proper controller numbers. Controller assignments for the Reason modules are in the "Reason controller charts" folder in EMID Resources
Multiple modules in Reason: addressable by MIDI channel, and by different pads and controls on MPD

Vyzex MPD editor instructions
Launch application
Click OK at MIDI Ports Setup
Wait! Image of the device will appear on screen.
Click on a pad or control to change it.
MIDI CH CC=current global channel (usually 1) You can set a pad or control to any channel, but use bank A (e.g., 1A)
Pads can be set to momentary or toggle (on/off). Pressure (aftertouch) can be on or off (don’t use Poly Pressure-PPr)
Here's what I was doing wrong today:
WHEN YOU HAVE SET A NOTE NUMBER, MOVE THE CURSOR OFF THE NOTE NUMBER—or else playing another pad will impose that pad’s note number on the current pad! (It's a feature: it lets you program the thing using a keyboard.)
Sliders can be set to controller number or Pressure.
Knobs similar, also option for NRPN—don’t use.
Click on name (“Generic”) to name your preset.
File>Save Set As….to save entire bank of presets. When you come back to the lab, File>Open to get it back.

Reason NN19 module: samples, with many of the same filtering and envelope parameters as Subtractor.

Feb 6

What are synth parameters?
In Subtractor:
Key number
Pitch, detune
Filter freq and resonance
Envelope, filter envelope
LFO rate and depth, mod envelope

Mapping keyboard physical gestures to musical ones: mod wheel and velocity
Mod wheel to pitch vibrato, volume vibrato, timbral change, envelope
velocity to amplitude
velocity upside down to volume
velocity to envelope attack time
velocity to filter envelope (brightness)

Use MIDI Monitor to check your incoming MIDI data.

Save the whole rack (.reason) in Reason: create your own folder in EMID Resources folder.

Feb 1

Familiar vs. unfamiliar user interfaces for music
Familiar: keyboard, guitar, drums, malletboard, violin, woodwind, brass. Advantage, people already know how to use it. Doesn't require new skills, practicing, rethinking how you make music.
Most commonly in electronic world: keyboard. Used with Moog synths, Switched-on Bach. Became glorified organs with thousands of stops, people play all of them the same way.
But, can extend technique to play keyboard in new way that has different expressive parameters (aftertouch, wheels, pedals).

Adaptive: or extended, like keyboard with pedals; stringless guitar; wind controllers with more buttons and levers than a conventional wind instrument; violins with sensors on the bow, etc.

Unfamiliar: like Theremin: hard for guitar or string players used to articulating with right hand. Using different parts of the body, or in different ways. Finger position or movement on surface or in free space. Relative positions of fingers -- spread or angle. Bend of joints: wrists, elbows, knees. Pressure on surface. Requires practice and mastery! Think of music in different ways than simple button-pushes/discrete events.

MIDI Hardware:
Traditionally uses MIDI cable, speed is limited to 31,250 bits/sec, about 1000 commands/sec. Other transports (USB, Firewire, Ethernet, Bluetooth) have much higher speed limit—essentially none.
Virtual MIDI connections (inside operating system, using software synths) also have no speed limit.
External devices communicate with computer using MIDI-USB interface or just USB, in which case computer must have software that recognizes the device. We have custom driver/patch for Max that recognizes Arduino.

MIDI command structure
Real-time control language.
Some commands three-bytes, some two, some one, some longer.
Often expressed in hexadecimal notation: 0-255 decimal ($)=00-FF Hex
Numbers below 128$ (80H) are data bytes. Numbers 128$-255$ are command bytes.
Channels: second half of command byte, 0-F=read as 1-16. Different insruments respond to different channels. In Reason, each module is on its own MIDI channel.
Note on (9n) + note number + velocity, off (velocity). Decimal ($): 144-159
Note off (8n)+ note # + velocity. Duration is time between on and off. 128-143$
NB: 9n with velocity zero is equivalent to note-off
Controller (Bn), controller number, value. Some continuous (wheel, slider, breath, foot control), some switched (sustain pedal). 127 of them, not all defined. Used for any kind of continuous command. 176-191$
Pitchbend: (En) + LSB + MSB. Like controller but its own command, double precision. 224-239$
Mono Aftertouch or Channel Pressure: (Dn) + value. 208-223$
Poly aftertouch (An) + note # + value. 160-175$ Reason doesn't respond to it.
Program change (Cn) 0-127. 192-207$ Reason doesn't respond to it.

Jan 25

An electronic musical instrument uses gestures to control electronic circuits.
Can be simple (direct) like theremin or complex (through microprocessor) like Wriggle Screamer.
Computers provide ultimate flexibility: they can produce any sound, and interpret any gesture however we like, once we get the gestural information into the computer.
The physical aspects of an instrument no longer have to have any relationship to the sounds it makes.

Two metaphors/paradigms for a new musical instrument:
1) Instrument metaphor:
Causes a sound to be made
Control of pitch(es)
Expressivity takes many forms:
Pitch articulation (more than just turning on a note)
Amplitude articulation (initial and subsequent)
Timbre articulation
2) Controller/Mixer metaphor:
Sequence or pattern generated automatically or by a single gesture.
Gestures control the parameters of the sequence as it plays.
Selection, adjustment, nudging, changing volume/balance/timbre on the fly

Basic things to think about when designing an instrument:
Depth & Virtuosity: As you learn it, you get better and can do more with it.
Something interesting to look at: Audience needs to pay attention, be able to connect what they see visually with what they hear.

Basic sound parameters
Pitch (inc. glide, bend)
timbre: waveform, filter freq, filter res, noise level
Envelopes of all (ADSR)
Vibrato (LFO) + vibrato envelopes

Jan 23

1) What's music? Varese: organized sound. Working definition: Sound that is created deliberately, with intent, and has interest as sound.

2) Elements of music: melody, rhythm/tempo, harmony, timbre/orchestration.
Elements of music performance: prescription, improvisation, interaction (and grey areas between)

3) What's a gesture controller? Something that responds to a physical action by one (or more) human beings. Examples: Squeeze, blow, pluck, bow, hit with hand or foot or stick, press with fingers.

How we do it—Links in the chain:
• Electronic sensors to detect gestures: touch, pressure/force, movement, acceleration, distance, displacement
• Framework to hold the sensors and make them playable.
• Device to turn data from sensors into MIDI: Arduinos
• Software to interpret and process the MIDI data: Max
• Synthesis software to turn the processed MIDI into sound: Reason, Max MSP
• Audio system to produce the sound

What we will do in the class:
• Study existing electronic instruments, see them demonstrated on video and live
• Conceptualize physical gestures as they can be used to make music
• Learn MIDI, what the commands mean, how they can be used to control music
• Learn Reason, a software synthesis system, and how to set its parameters
• Translate gestures into electronic form, using sensors, and then translate them into MIDI using Arduinos
• processing real-time MIDI data with MAX
• Building new controllers and systems
• Work in teams of students with complementary skillsets
• at the end, do a public demonstration

Resources: Course pack (buy at Gnomon Copy), What’s MIDI (buy from me or at Music office, if you didn't take Music 64 or 65), reference books, manuals and catalogs in lab, on computers, and on-line.

Lab: Electronic parts and tools, sensors, software, mechanical parts, hand and power tools for woodworking and assembly. 3D printer.

Laser cutter, more tools in Bray Labs and at CEEO at 200 Boston Ave. Available to all with simple training.