watt

A live MIDI sequencer input for the Digitech Whammy IV

About

The Digitech Whammy is a guitar effects pedal that includes a number of pitch-shifting effects. It has a MIDI input that can be used to control all the settings on the pedal.

watt turns the Whammy into a sequencer by playing programs into the MIDI in. A program cannot control the input pitch, only the effects added to the input pitch. So rather than defining absolute pitches, a program defines output intervals based on the input to the pedal.

The result is a unique sounding programmable pitch shifter than can make a guitar or any other input sound like a polyphonic synth and sequencer while not destroying the characteristics of the original signal.

A number of key commands are available to allow live modification to the program or the effect currently playing.

Above all watt is a technology-in-music experiment created to explore composition through programming without losing the live component that makes music spontaneous.

Requirements

• Digitech Whammy IV
• midi cable
• computer with a midi output running OSX, WIndows, or Linux
• pygame

Usage

####Programs

List the available programs:

python watt.py -l

Run a program:

python watt.py -p [program]

This will run a sequencer program in a loop.

While a program is running you can adjust the BPM using the keyboard:

+ : go faster

- : go slower

####Live Run without a program:

python watt.py

This will put watt in octave mode with no sequencer. Use these keys like a keybaord:

  w   e        t   y   u
a   s   d   f   g   h   j   k

These will map to the following intervals from the input pitch:

  m2 m3      A4 m6 m7
P1 M2 M3 P4 P5 M6 M7 P8

Composition

watt programs are not easy to create yet, but there are a couple of tricks:

• Feed a tone generator into the pedal while composing (a looping pedal works great for this)
• Use the live keyboard to write melodies and sequences

Thinking in intervals is a great exercise for learning composition.

Future possibilities

• more program banks
• more live controls
• MIDI file input/output support
• recording live key commands to a program
• audio input as a control source
• a watt hardware device