10 Services from music-theory.x402tookit.com

Converts a frequency in Hz to the nearest musical note, MIDI number, and cents offset, with adjustable A4 reference pitch.

Transposes a chord progression by a given number of semitones or between two keys, returning correctly spelled output chords for the target key.

Returns the notes, degrees, semitone intervals, step patterns, MIDI numbers, and pitch classes for any named scale or mode on a given root note.

Spells a chord from its symbol (e.g. Cmaj7, F#m7b5, Dsus4, C/E) returning notes, intervals, semitones from root, and MIDI numbers.

Identifies the best chord name, inversion, and alternative names from a set of input notes, treating the first note as the bass.

Analyzes a chord progression in a given key and returns Roman numeral notation including inversions, borrowed chords, and secondary dominants.

Calculates the interval between two notes (quality, number, semitones) or finds the note a given interval above or below a starting note.

Converts a BPM tempo into delay times and note durations in milliseconds, or averages tap intervals into a steady BPM value.

Converts a note name (e.g. C#4, Bb3) or MIDI number to its MIDI value, frequency in Hz, and wavelength in cm, with an adjustable A4 reference pitch.

Returns key signature details (sharps/flats, accidentals), circle-of-fifths position and neighbours, and relative/parallel keys for any major or minor key.