Building a Music Step Sequencer with Vue.js

Getting Started

In this tutorial, we’ll explore the versatility of Vue.js by building a simple yet fully functional music step sequencer. We’ll combine Vue with Vuetify and howler.js to create an interactive app that allows users to create and save beats.

Before we dive in, make sure you have Node.js, Vue, and Vue CLI installed on your machine.

Setting Up the Project

Create a new Vue project using Vue CLI, and add Vuetify and howler.js to the project.

vue create my-music-sequencer
cd my-music-sequencer
vue add vuetify
npm install howler

Clean up the default project by deleting unnecessary files and configuring the project structure.

Building the App Template

Create a base app template using Vuetify’s v-card and v-toolbar components. Add a title bar and a blank page to get started.

<template>
  <v-app>
    <v-toolbar>
      <v-toolbar-title>Music Step Sequencer</v-toolbar-title>
    </v-toolbar>
    <v-card>
      <v-card-text></v-card-text>
    </v-card>
  </v-app>
</template>

Adding Audio Functionality

Set up the base audio functionality by including four sound sample files (kick, snare, hi-hat, and shaker) and creating an instance of the audio context.

import { Howl } from 'howler';

const kick = new Howl({ src: ['kick.mp3'] });
const snare = new Howl({ src: ['snare.mp3'] });
const hiHat = new Howl({ src: ['hi-hat.mp3'] });
const shaker = new Howl({ src: ['shaker.mp3'] });

const audioContext = new AudioContext();

Define properties for tempo, tracks, and playback control.

Creating the SoundTracks Component

Create a SoundTracks component to render the tracks. Pass a tracks prop to the component and define methods for playing and stopping sounds.

<template>
  <div>
    <v-switch v-model="track.isPlaying" @change="playOrStopSound(track)" />
    <v-button-toggle>
      <v-btn @click="playSound(track)">Play</v-btn>
      <v-btn @click="stopSound(track)">Stop</v-btn>
    </v-button-toggle>
  </div>
</template>

<script>
export default {
  props: {
    tracks: Array
  },
  methods: {
    playOrStopSound(track) {
      if (track.isPlaying) {
        this.playSound(track);
      } else {
        this.stopSound(track);
      }
    },
    playSound(track) {
      // Play sound logic
    },
    stopSound(track) {
      // Stop sound logic
    }
  }
}
</script>

Creating the SoundControls Component

Create a SoundControls component to handle playback, tempo, and metronome functionality. Pass props for tempo, counter, and isPlaying, and define methods for playing, stopping, and updating the tempo.

<template>
  <div>
    <v-slider v-model="tempo" @input="updateTempo" />
    <v-btn @click="play">Play</v-btn>
    <v-btn @click="stop">Stop</v-btn>
  </div>
</template>

<script>
export default {
  props: {
    tempo: Number,
    counter: Number,
    isPlaying: Boolean
  },
  methods: {
    updateTempo() {
      // Update tempo logic
    },
    play() {
      // Play logic
    },
    stop() {
      // Stop logic
    }
  }
}
</script>

Creating the SoundPresets Component

Create a SoundPresets component to save and load beats presets. Define properties for currentPreset, dialog, presetName, and userPresets. Create methods for clearing tracks, loading presets, saving presets, and deleting presets.

<template>
  <div>
    <v-dialog v-model="dialog">
      <v-card>
        <v-card-text>
          <v-text-field v-model="presetName" />
        </v-card-text>
        <v-card-actions>
          <v-btn @click="savePreset">Save</v-btn>
          <v-btn @click="deletePreset">Delete</v-btn>
        </v-card-actions>
      </v-card>
    </v-dialog>
  </div>
</template>

<script>
export default {
  data() {
    return {
      currentPreset: null,
      dialog: false,
      presetName: '',
      userPresets: []
    }
  },
  methods: {
    clearTracks() {
      // Clear tracks logic
    },
    loadPreset(preset) {
      // Load preset logic
    },
    savePreset() {
      // Save preset logic
    },
    deletePreset() {
      // Delete preset logic
    }
  }
}
</script>

Putting it All Together

Include the components in the app template and add event listeners to handle user interactions. Use Vue’s computed properties and watchers to update the app state.

Final Result

Congratulations! You’ve built a fully functional music step sequencer using Vue.js, Vuetify, and howler.js. This project demonstrates the versatility of Vue and its ability to integrate with other libraries to create complex applications.

Debugging and Monitoring

To take your Vue app to the next level, consider using a debugging and monitoring tool to track application state and identify issues.

• Monitor application state: Track changes to your app’s state and identify issues.
• Aggregate and report on issues: Get insights into errors and performance problems.