Random Musical Note

The Chromatic Scale and Randomness

The chromatic scale contains twelve notes, each separated by one semitone: C, C#, D, D#, E, F, F#, G, G#, A, A#, B. These twelve pitches form the complete vocabulary of Western tonal music. Every melody, chord, and harmony draws from this set. The generator selects one at random with a probability of exactly 1/12 (approximately 8.33%) per note.

Equal Temperament

Modern pianos and digital instruments use twelve-tone equal temperament, a tuning system where each semitone corresponds to a frequency ratio of 2^1/12, approximately 1.05946. This means multiplying any note's frequency by 1.05946 produces the next semitone up. Twelve such steps yield exactly a factor of 2, which is the octave. The international standard A440, adopted by the ISO in 1955, fixes the note A at 440 Hz. Every other frequency follows from this single reference point and the equal-temperament ratio.

Sound and the Browser

Each note on this page plays through the Web Audio API, a W3C standard built into every modern browser. A triangle-wave oscillator generates the pitch at the mathematically exact frequency. The sound is synthesized entirely on your device. No audio files are downloaded. No server involvement. Tap the piano keys above to explore all twelve notes freely.

Color and Sound

The colors assigned to each note follow a chromatic mapping: twelve notes spread evenly across the 360° hue wheel. C begins at red (0°), and each subsequent semitone advances 30°. Alexander Scriabin, the Russian composer, designed a "color keyboard" for his 1910 orchestral work Prometheus: The Poem of Fire, mapping musical keys to specific colors for a light organ that would illuminate the concert hall.

The Coupon Collector's Problem

The "Unique" statistic tracks a classic question in probability theory: how many random draws does it take to see every possible outcome at least once? With 12 notes, the expected number is 12 × (1 + 1/2 + 1/3 + … + 1/12) ≈ 37.2. Keep generating and watch how long it takes for all 12 segments of the histogram to light up.

Your Random Melody

The "Play Session" button below the statistics replays every note you have generated in order, creating an accidental melody from pure randomness. Adjust the tempo to hear the sequence as a slow meditation or a rapid arpeggio. Musicians have long used chance procedures as creative tools. John Cage famously composed Music of Changes (1951) using the I Ching to determine pitches, durations, and dynamics. Your session history is a miniature version of the same idea: randomness as a starting point for musical discovery.

In the Classroom

This tool serves as a composition prompt and ear-training exercise. Generate a sequence of random notes and play them back as a melodic seed. Students can rearrange the random sequence into a melody, discovering how context transforms arbitrary pitches into musical phrases. The sound playback provides immediate auditory reference. The tool requires no accounts, stores no data, and runs entirely in the browser.

Private by Architecture

Every note is selected and played entirely within your browser using the Web Cryptography API for randomness and the Web Audio API for sound. The server delivers the page; your device creates every outcome and every sound.