Live Demo - Advanced Organ Composition with Markov Chains
- Overview
- Features
- How to Use
- Techniques and Strategies
- Computer Science Techniques
- Music Theory Techniques
This project demonstrates an advanced organ composition system using Markov Chains. The system allows users to generate and manipulate organ music through various controls and strategies. The composition is driven by Markov Chains to determine the next chord and melody strategies, creating a dynamic and evolving musical piece.
- Tempo Control: Adjust the tempo of the composition between 60 and 180 BPM.
- Volume Control: Control the master volume, chord volume, and melody volume independently.
- Reverb Control: Adjust the intensity of the reverb effect.
- Waveform Selection: Choose different waveforms for chords and melody (Sine, Triangle, Sawtooth, Square).
- Mute Controls: Mute or unmute chords and melody separately.
- Visual Feedback: Display the current chord, melody, and strategies being used.
- Console Logs: View detailed logs of the composition process, including rhythm patterns and frequency information.
- Dark Mode: Toggle between light and dark modes for better visual comfort.
- Equalizer: Adjust the gain for different frequency bands (60 Hz, 170 Hz, 350 Hz, 1000 Hz, 3500 Hz, 10000 Hz).
- Open the Live Demo: Click on the Live Demo link to open the application in your browser.
- Adjust Controls: Use the sliders and dropdowns to adjust the tempo, volume, reverb intensity, waveforms, and equalizer settings.
- Tempo: Move the slider to set the tempo (BPM).
- Master Volume: Adjust the overall volume of the composition.
- Chord Volume: Adjust the volume of the chords.
- Melody Volume: Adjust the volume of the melody.
- Reverb Intensity: Adjust the intensity of the reverb effect.
- Chord Waveform: Select the waveform for the chords.
- Melody Waveform: Select the waveform for the melody.
- Equalizer: Adjust the gain for different frequency bands using the EQ sliders.
- Mute/Unmute: Click the "Mute Chords" or "Mute Melody" buttons to mute or unmute the respective parts.
- Play/Stop: Click the "Play" button to start the composition. Click the "Stop" button to stop the composition.
- Visual Feedback: Observe the current chord, melody, and strategies in the visual feedback section.
- Console Logs: View detailed logs in the console section to see the rhythm patterns, frequencies, and other information.
- Dark Mode: Toggle the "Dark Mode" checkbox to switch between light and dark modes.
The system uses various chord strategies within the key of C Major. These strategies are determined by a Markov Chain, which transitions between different chord types based on predefined probabilities.
- Tonic: C major 7
- Dominant: G major 7
- Subdominant: F major 7
- Minor: D minor 7
- Diminished: B diminished 7
- Suspended: C suspended
- Minor7: D minor 7
- Augmented: C augmented
The melody is generated using different strategies, also determined by a Markov Chain. Each strategy produces a unique melodic pattern.
- Stepwise: Generates a melody that moves in small steps.
- Leap: Generates a melody with larger intervals.
- Motif: Repeats a short melodic motif.
- Arpeggio: Uses arpeggios to create the melody.
- Pentatonic: Uses the pentatonic scale.
- Blues: Uses the blues scale.
- Chord Tones: Prioritizes chord tones in the melody.
- Ascending Run: Creates an ascending melodic run.
- Descending Run: Creates a descending melodic run.
- Random Walk: Generates a random walk through the scale.
The rhythm of the melody is determined by predefined patterns, which are randomly selected for each iteration.
- Pattern 1: [1, 0.5, 0.5, 1, 0.5, 0.5, 1]
- Pattern 2: [1, 1, 0.5, 0.5, 1, 1, 1]
- Pattern 3: [0.5, 0.5, 0.5, 0.5, 1, 1]
- Pattern 4: [1, 0.25, 0.25, 1, 0.5, 0.5, 1]
- Pattern 5: [0.25, 0.25, 0.5, 0.5, 1, 1, 1]
- Pattern 6: [1, 1, 1, 1, 0.5, 0.5, 0.5, 0.5] (Triplets)
- Pattern 7: [1, 0.5, 1, 0.5, 1, 0.5, 1] (Balanced pattern)
- Pattern 8: [1, 1, 0.75, 0.25, 1, 1] (Simplified dotted rhythms)
Markov Chains are pivotal in determining the subsequent chord and melody strategies. Essentially, a Markov Chain is a stochastic model that represents a sequence of possible events, where the likelihood of each event is contingent solely on the state achieved in the preceding event. In this project, Markov Chains facilitate the transition between various chord and melody strategies, guided by predefined probabilities. This ensures a coherent and musically pleasing progression.
To manage the precise timing of notes, the composition employs an event scheduling system. The scheduler function is integral to this system, ensuring that notes are played at the correct intervals. It achieves this by scheduling events in advance and utilizing a lookahead interval to maintain accurate timing. This method is crucial for synchronizing the different elements of the composition.
The project leverages the Web Audio API for sound generation and manipulation. For each note, oscillators are created, and a variety of audio nodes (such as gain nodes, filters, and panners) are employed to shape the sound. The createOrganOscillator function plays a key role in this process, crafting a rich organ sound by layering multiple oscillators and applying various filters and effects. This results in a complex and textured audio output.
User interaction is handled through event listeners, which respond to changes in the controls. For instance, sliders and buttons allow users to adjust parameters like tempo and volume. The addEventListener method is used to attach these event handlers to the corresponding DOM elements, enabling real-time interaction and customization of the composition. This interactive component enhances the user experience by providing intuitive control over the musical output.
The project uses various chord progressions within the key of C Major. Chord progressions are sequences of chords that are used to create harmony in music. The system transitions between different chord types (e.g., tonic, dominant, subdominant) based on the probabilities defined in the Markov Chain.
Melodies are generated using different strategies that define how the notes are selected and arranged. For example, the stepwise strategy generates melodies that move in small steps, while the leap strategy generates melodies with larger intervals. The melody strategies are designed to create interesting and varied melodic patterns.
The project uses different scales to generate melodies. For example, the pentatonic scale and the blues scale are used in some of the melody strategies. Scales are sequences of notes that are used as the basis for melodies and harmonies in music.
Rhythm patterns define the timing and duration of notes in the melody. The project uses predefined rhythm patterns that are randomly selected for each iteration. Rhythm patterns add variety and interest to the composition by varying the timing and duration of notes.
This project demonstrates the use of Markov Chains and the Web Audio API to create an advanced organ composition system. By combining computer science techniques with music theory, the system generates dynamic and evolving musical pieces that can be controlled and manipulated by the user. Explore the live demo to experience the full capabilities of the system.