To see an example of an end product watch this video

Installation

$ npm install @briblanch/lightman --save

Overview

Lightman is a node js library that allows you perform any action when certain note sequences are played in a song using a midi compatible device (keyboard, guitar, etc). Lightman is often used to control lights, but it can do anything you can put your mind to.

Usage

let Lightman = require('@briblanch/lightman');

let songDir = __dirname + '/songs';

var app = Lightman.createApp(songDir);
app.start();

Explanation

First off, there are three different parts to a song that Lightman needs to know about:

1. The overall Song.
2. The different Elements in a song, such as an intro, verse, chorus, bridge, etc.
3. The different Sequences in an element, or the notes or chords that are played.

Sometimes is is just better to explain things by example, so for the sake of demonstration I am going to use the song The Scientist by Coldplay (one of my favorites to play) to demonstrate how to take different elements and sequences in a song and build them using Lightman.

The Scientist consists of three different elements:

1. The verse (can group the intro into the verse because the chord progression is the same)
   • Consists of the chords Dm7, Bb, F, and Fsus2
   • Played twice throughout song
   • Chord Sequences repeat 6 times within the verse
   • The chorus is played after the verse
2. The chorus
   • Consists of the chords Bb, F, and Fsus2. On the second time through the chorusthe chord progression is the same but C is played after the Fsus2
   • Played twice in the song
   • Chord sequences are repeated twice within the chorus
   • The verse is played after the first time through the chorus, the bridge is played after the second time.
3. The bridge
   • Consists of the chords Dm7, Bb, and F
   • Played once throughout the song
   • Chord sequences are repeated 5 times withing the bridge
   • Nothing comes after the bridge

A song object for The Scientist might look something like this:

let notes = require('@briblanch/lightman').notes;

let theScientist = {
  name: 'The Scientist', // Name of the song
  hook: [notes.f4, notes.b4b, notes.c5], // The song hook. This is how Lightman knows what song to play.
  startingElement: 'verse', // The starting element of the song, defaults to 'intro'
  backingTrack: __dirname + '/../backing_tracks/thescientist.mp3', // Absolute path to the backing track
  onCancel() { //
    // Perform some action if the song is cancelled
  },
  elements: { // Object of elements
    verse: {
      repeats: 6, // Number of times this element repeats. Either an int or an array of ints.
      nextElement: 'chorus', // The element after this one. Either a string or an array of strings.
      sequences: [ // Array of sequences in the order the chords are played
        {
          notes: [notes.c4, notes.f4, notes.a4], // Notes to recognize this sequence. Array of 'notes'.
          action(seqTimesPlayed, elTimesPlayed) { // Called when 'notes' are played 'repeat' number of times
            // seqTimesPlayed: How many times this sequence has been repeated within this played of the element
            // elTimesPlayed: How many times the element has been played through the whole song
            // This is where the magic happens. You can do anything you want when 'action' is called.
          },
        },
        {
          notes: [notes.c4, notes.f4, notes.g4] // Since this is the last sequence, repeat the element
        }
      ]
    },
    chorus: {
      repeats: 2, // The 'chorus` repeats twice.
      nextElement: ['verse', 'bridge'],
      sequences: [
        {
          notes: [notes.d4, notes.f4, notes.b4b],
          actionRepeats: 1,
          action(seqTimesPlayed, elTimesPlayed) {}
        },
        {
          notes: [[notes.c4, notes.f4, notes.g4], [notes.c4, notes.e4, notes.g4]],
          repeats: [1, 5],
          action(seqTimesPlayed, elTimesPlayed) {}
        }
      ],
      onEnd(timesPlayed) {
        // Called when the element is repeated 'repeats` times.
      }
    },
    bridge: {
      repeats: 3,
      nextElement: 'chorus',
      sequences: [
        {
          notes: [notes.c4, notes.f4, notes.a4],
          actionRepeats: 1, // Only call the 'action' function this many times
          action(seqTimesRepeated, elTimesRepeated) {}
        },
        {
          notes: [notes.d4, notes.f4, notes.b4b]
        },
        {
          notes: [[notes.c4, notes.f4, notes.a4], [notes.c4, notes.f4, notes.a4], [notes.c5]] //
        }
      ],
      onEnd() {}
    }
  }
}

module.exports = theScientist;

Example

To see Lightman working in a complete application, checkout my other project Lightshow!

Docs

Lightman

Modes

• CONFIG - Lightman is waiting to be told what song to listen for. Listens for a three note riff corresponding to a Songs hook property. After 3 notes are hit and a song is not recognized, the configNote must be hit again to do attempt another recognition attempt.
• SONG - Lightman is currently tracking progress through a song.

Note: Lightman is launched in CONFIG mode

notes

let notes = Lightman.notes;

...

{
    notes: [notes.c3, notes.f4s, notes.b4b]
}

...

Notes module to be used when building songs.

• Notes that end in s are sharp notes
• Notes that end in b are flat notes

Lightman.createApp()

let app = Lightman.createApp(songsOrDir[, options]);

Creates an instance of Lightman

• songsOrDir:<Array|String> - Either an array of Song objects or the directory where all the song objects are.
• Options:<Object> - An object of options.
  • configNote:<note> - The note that puts Lightman in CONFIG mode. Default: notes.c8
  • onConfig() - The function that is called when the app is put into CONFIG mode.
  • midiPort:<Int>: The midi port to open. Default: 0.
  • testing<Boolean>: When true, Lightman will open a virtual port instead of a hardware port. Default: false

start()

app.start()

When called, Lightman will open the midi input port and listen for midi signals.

Song

The overarching song object.

Properties

• name:<String> - The name of the song.
• hook:<Array> - The three note riff that identifies a song. Must be unique.
• startingElement:<String> - The starting element of a song. Default: 'intro'.
• backingTrack:<String> - The absolute path to a backing track. Supports only .mp3 files currently.
• elements:<Object<Element>>: An object of Elements.
• onCancel() - A function called when Lightman is put in CONFIG mode before a song completes. This is useful to stop any light intervals that are running, etc.

Element

Properties

• repeats:<Int|Array<Int>> - An integer or array of integers that tells Lightman how many times to repeat the element. If it is an integer, Lightman will repeat the element that many times every time the element is played. If it is an array, Lightman will repeat the number of each index in the array in order. For example, repeats: [2, 3] would repeat 2 times the the first time the element is played and 3 times the second time the element is played.
• nextElement:<String:Array<String>> - The key or keys of element(s) to play after the current element is finished. If it is a String, Lightman will play the element specified every time after the current element finishes. If it is an array, Lightman will play the specified next elements in order every time the element is played. If the number of times the element has been played exceeds the length of the array, the song is over.
• sequences:<Array<Sequence>> - An array of Sequences in order they are played throughout the parent element.
• onEnd(timesPlayed) - A function that is called when the element has finished playing.
  • timesPlayed:<Int> - The number of times that element has been played. This is zero based so after the first time an element has been played, timesPlayed will be 0.

Sequence

Properties

• notes:<Array<Note>> - An array of notes that Lightman listens.
• repeats:<Int|Array<Int>> - An integer or array of integers that tells Lightman how many times notes must be repeated before the sequence is recognized. If it is an integer, Lightman will wait to recognized the sequence that many times every time the sequence is played. If it is an array, Lightman will wait to recognized the sequence until the value in the array, in order. For example, repeats: [2, 3] would wait to recognized the sequence till it has been played 2 times the first time the sequence is played and 3 times the second time the sequence is played.
• action(seqTimesPlayed, elTimesPlayed) - The function that is called when notes is recognized repeats times.
  • seqTimesPlayed:<Int> - The number of times the sequence has been repeated in the current playing of the parent element.
  • elTimesPlayed:<Int> - The number of times the parent element has been played throughout the whole song.
• actionRepeats:<Int> - The number of times action will be called. Useful if you only want action called the first time a sequence is recognized.

Contact

Developed and tested by Brian Blanchard

• Email: briblanch@gmail.com
• Twitter: @briblanch
• GitHub: briblanch

License

MIT