Simple melody

Adding constraints or limitations to the construction of your melody can make you creative

Recently I went through a (free) course on artofcomposing.com and learnt that adding constraints or limitations to the construction of your melody can make you creative. Here are the basic constraints this course suggested as a starting point:

• Select a root note and scale
• Use only chord tones from the selected scale
• Use only half notes, eighth notes and quarter notes

Before we go on, here’s a sample of what we are gonna end up creating using Scribbletune

Using the constraints the instructor created a simple melody. He laid out the chord progression I I V I for the C Major scale and randomly chosing between quarter notes and eigth notes. Of course he was a trained musician with a lot more to offer than just that but I thought this simple technique can easily be implemented with Scribbletune for creating simple melodies.

Create a file called simpleMelody.js and require scribbletune,

const scribble = require('scribbletune');

So lets select the C minor scale for our example and decide to use the progression i iii ii v. We can get the actual chords like this,

const chords = scribble.getChordsByProgression('C4 minor', 'i iii ii v');

This will set chords to a string that looks like Cm-4 Gm-4 Cm-4 Dm-4. The number after the hyphen indicates the octave. In Ableton Live the middle C is on the third octave, hence the 4 you see here will transpose to 3 in Ableton live. I have an article that explains middle C a bit more. You can read it if that interests you.

Since we have 4 chords, we can start accumulating notes and a pattern too. Lets start by initializing them,

const notes = [];
let pattern = '';

Next, we ll loop over the 4 chords and decide at each chord if we want to use 2 quarter notes or 1 quarter note and 2 eighth notes. We can either use Math.random() to determine this or we can do it based on some other condition. For instance we’ll do a modulo on the current index in the loop.

chords.split(' ').forEach((chordName, index) => {
  // Get the chord as an array of notes
  const chord = scribble.chord(chordName);

  if (index % 2 !== 0) {
    // Use 2 quarter notes
    pattern = pattern + 'xx';

    // Since we are using 2 notes, we ll push the first 2 notes from the chord into the notes array
    // You could very well use 2 random notes, but we ll keep things straightforward for now
    notes.push(chord[0]);
    notes.push(chord[1]);

  } else {
    // Use a quarter note and 2 eigth notes
    pattern = pattern + 'x[xx]';

    // Since we are using 3 notes in all, we ll push all 3 notes of the chord to the notes array
    notes.push(chord[0]);
    notes.push(chord[1]);
    notes.push(chord[2]);
  }
});

At the end of this, we should now have a bunch of notes and a pattern. Let’s create a clip out of these and render it out as a MIDI file:

const clip1 = scribble.clip({
  notes,
  pattern
});

scribble.midi(clip1, 'clip1.mid')

Additionally, to make it sound interesting, let’s create another clip with a longer note length but the same notes and pattern. In Scribbletune note lengths are set to 4n (quarter notes) by default. We can change this by using the subdiv property. For this example, we ll create a clip which uses 2n (half notes) as the subdiv (which sets default note length).

const clip2 = scribble.clip({
  notes,
  pattern,
  subdiv: '2n'
});

scribble.midi(clip2, 'clip2.mid')

Running node simpleMelody.js should produce 2 MIDI files: clip1.mid and clip2.mid. Here’s how it sounded like when I rendered the MIDI files with i iii ii v and ii III ii v in Ableton Live. For clip1.mid I used NI’s Reaktor Factory Libray synthesizer Junatic and for clip2.mid I used Ableton’s stock synth preset Epic Trance Lead. I added a beat and a riser effect to make it sound a little nicer. Here it is again ;)

And finally, here’s the script in it’s entirety.