General theory

Here are some links to some of the key ideas underlying tuning:

Basics

• Ratio
  • Ratio math
• Cent
• Chords
• Scales
• Notation

Core Concepts

• Just intonation
• Regular temperaments
• Equal-step tuning
• Periods and generators
• EDO
• EDT
• MOS scale
• Periodic scale
• Arithmetic tuning
• Comma pump

Javascript tools

• Interval calculator – a nice online interval calculator tool, shows linear fraction and EDO fraction expansions, too
• An animated Javascript Moment of Symmetry (MOS) ring demo, another untwelve.org creation
• An excellent Firefox browser tuning demo synthesizer, 'Wicksynth'

See also: List of Music Software#Browser Based

Additional Stuff

• Chord of nature
• Diatonic, Chromatic, Enharmonic, Subchromatic
• Indexes of small scales:
  • Category:5-tone scales
  • Category:6-tone scales
  • Category:7-tone scales
  • Category:8-tone scales
  • Category:9-tone scales
  • Category:10-tone scales

Advanced Theory

Main article: Mathematical Theory

• ABC, High Quality Commas, and Epimericity
• Benedetti height
• Cluster temperament
• Consonant class scale
• Distributional Evenness
• Essential tempering commas
• Generator complexity
• Graham complexity
• Kees height
• Lumma stability
• Maximum variety
• Modal UDP Notation
• Tenney height