music_theory Namespace Reference

A dependency-free, header-only collection of useful functions for music theory. More...

Classes
class	Transposer
	Provides dependency-free transposition utilities that work with any scale that has 7 diatonic steps and an equal number of divisions of the octave (EDO). The most common Western scales use 12 divisions of the octave, .i.e., 12-EDO. More...

Enumerations
enum class	DiatonicMode : int {   Ionian = 0 , Dorian = 1 , Phrygian = 2 , Lydian = 3 ,   Mixolydian = 4 , Aeolian = 5 , Locrian = 6 }
	Represents the seven standard diatonic musical modes. More...

Functions
int	calcDisplacement (int pitchClass, int octave)
	Calculates the displacement value for a given absolute pitch class and octave.
template<typename T >
constexpr T	sign (T n)
	Calculates the sign of an integer.
template<typename T >
constexpr T	signedModulus (T n, T d)
	Calculates the modulus of positive and negative numbers in a predictable manner.

Variables
constexpr int	STANDARD_DIATONIC_STEPS = 7
	currently this is the only supported number of diatonic steps.
constexpr int	STANDARD_12EDO_STEPS = 12
	this can be overriden when constructing a Transposer instance.

Detailed Description

A dependency-free, header-only collection of useful functions for music theory.

Enumeration Type Documentation

DiatonicMode

enum class music_theory::DiatonicMode : int

strong

Represents the seven standard diatonic musical modes.

Values correspond to their roots with no sharps or flats C (0) through B (6).

Enumerator
Ionian	major
Dorian	minor with raised 6
Phrygian	minor with flat 2
Lydian	major with raised 4
Mixolydian	major with flat 7
Aeolian	natural minor
Locrian	diminished with flat 2 and 5

Function Documentation

calcDisplacement()

int music_theory::calcDisplacement ( int  pitchClass, int  octave  )

inline

Calculates the displacement value for a given absolute pitch class and octave.

Parameters

pitchClass	0..6 corresponding to C..B
octave	Octave 4 is the middle-C octave

Returns

A displacement value that can be used to create a Transposer instance.

sign()

template<typename T >

constexpr T music_theory::sign ( T  n )

inlineconstexpr

Calculates the sign of an integer.

Parameters

n	The integer to process.

Returns

-1 for negative; 1 for non-negative.

signedModulus()

template<typename T >

constexpr T music_theory::signedModulus ( T  n, T  d  )

constexpr

Calculates the modulus of positive and negative numbers in a predictable manner.

Template Parameters

T	an integer type

Parameters

n	The number (positive or negative) for which to calculate the modulus
d	The base of the modulus. This must be a positive number.

Returns

For non-negative, the result is the same as %. For negative numbers, the result is -1 * (abs(n) % d).