Table of Contents

• Meantonal
• Installation
• Documentation

Meantonal

Meantonal is a specification for representing pitch information in Western music, and a suite of tools for operating on this information. It's a small, focused library that aims to empower developers to build musical apps more easily.

Meantonal is:

• Flexible with I/O: easily ingest and translate between Scientific Pitch Notation, Helmholtz notation, ABC and Lilypond. Extract MIDI values at any time.
• Semantically nondestructive: the distinction between enharmonic notes such as C♯ and D♭ is maintained. Things that don't behave the same way musically are not encoded the same way in Meantonal.
• Just vectors: under the hood pitches and intervals are 2d vectors. Operations are simple to understand, surprisingly powerful, and fast to execute.
• Tuning-agnostic: Target any meantone tuning system, not just 12-tone equal temperament. You want 31 tones per octave? Done.

For the JS/TS implementation of Meantonal click here, or for the C implementation click here.

Installation

Adding Meantonal to your project is as simple as running:

pip install meantonal

You're now ready to import and use Meantonal's classes.

from meantonal import SPN, Helmholtz, Interval, TonalContext, MirrorAxis

p = SPN.to_pitch("C4")
q = Helmholtz.to_pitch("e'")

m = p.interval_to(q)  # M3
n = Interval.from_name("M3")

m.is_equal(n)  # True

context = TonalContext.from_strings("Eb", "major")

q = q.snap_to(context)  # q has now snapped to Eb4

axis = MirrorAxis.from_spn("D4", "A4")

q = q.invert(axis)  # q is now G#4

Since pitches and intervals are just vectors, the Python implementation also supports natural arithmetic on them, in the style of datetime/timedelta:

from meantonal import SPN, Interval

p = SPN.to_pitch("C4")
m = Interval.from_name("M3")

q = p + m       # E4 -- same as p.transpose_real(m)
q - p           # M3 -- same as Interval.between(p, q)
p - m           # Ab3 -- transpose down
m + m           # A5 (augmented 5th) -- same as m.add(m)
-m              # descending M3 -- same as m.negative
m * 3           # A7 -- same as m.times(3)

Documentation

A full reference of the Python implementation of Meantonal can be found here