---
title: "Theory reference · Piakno"
description: "Where middle C is, how to read a time signature, what a dominant 7th chord is — the concepts the course teaches, each one written as a direct answer that points back at the lesson it comes from."
url: "https://piakno.com/theory"
lang: "en"
alternates:
  en: "https://piakno.com/theory.md"
  zh-Hans: "https://piakno.com/zh-Hans/theory.md"
  zh-Hant: "https://piakno.com/zh-Hant/theory.md"
  ja: "https://piakno.com/ja/theory.md"
  ko: "https://piakno.com/ko/theory.md"
  es: "https://piakno.com/es/theory.md"
  de: "https://piakno.com/de/theory.md"
  pt-BR: "https://piakno.com/pt-BR/theory.md"
---

# Theory reference

> Where middle C is, how to read a time signature, what a dominant 7th chord is — the concepts the course teaches, each one written as a direct answer that points back at the lesson it comes from.

- [Middle C](https://piakno.com/theory/middle-c)
- [Treble and bass clef](https://piakno.com/theory/treble-and-bass-clef)
- [Ledger lines and 8va](https://piakno.com/theory/ledger-lines-and-octave-signs)
- [Sharps, flats, and naturals](https://piakno.com/theory/sharps-and-flats)
- [Repeat signs](https://piakno.com/theory/repeat-signs)
- [Note values](https://piakno.com/theory/note-values)
- [Time signature](https://piakno.com/theory/time-signature)
- [Rests](https://piakno.com/theory/rests)
- [Dotted notes](https://piakno.com/theory/dotted-notes)
- [Triplets](https://piakno.com/theory/triplets)
- [6/8 time](https://piakno.com/theory/compound-time)
- [Whole steps and half steps](https://piakno.com/theory/whole-and-half-steps)
- [Key signature](https://piakno.com/theory/key-signature)
- [The circle of fifths](https://piakno.com/theory/circle-of-fifths)
- [Minor scales](https://piakno.com/theory/minor-scale)
- [Modes](https://piakno.com/theory/modes)
- [Pentatonic and blues scales](https://piakno.com/theory/pentatonic-and-blues-scales)
- [Intervals](https://piakno.com/theory/intervals)
- [Major and minor triads](https://piakno.com/theory/major-and-minor-triads)
- [Chord inversions](https://piakno.com/theory/chord-inversions)
- [Roman numerals](https://piakno.com/theory/roman-numerals)
- [Harmonic function](https://piakno.com/theory/harmonic-function)
- [The dominant seventh chord](https://piakno.com/theory/dominant-seventh)
- [Seventh chords](https://piakno.com/theory/seventh-chords)
- [Cadences](https://piakno.com/theory/cadences)
- [Figured bass](https://piakno.com/theory/figured-bass)
- [Secondary dominants](https://piakno.com/theory/secondary-dominants)
- [Chord symbols](https://piakno.com/theory/chord-symbols)
- [The ii–V–I progression](https://piakno.com/theory/ii-v-i)
- [Extended chords](https://piakno.com/theory/extended-chords)
- [Tritone substitution](https://piakno.com/theory/tritone-substitution)
- [Borrowed chords](https://piakno.com/theory/borrowed-chords)
- [Pop chord progressions](https://piakno.com/theory/pop-chord-progressions)
- [The 12-bar blues](https://piakno.com/theory/twelve-bar-blues)
- [AABA song form](https://piakno.com/theory/song-form)
- [Piano fingering numbers](https://piakno.com/theory/piano-fingering)
- [Passing the thumb under](https://piakno.com/theory/thumb-under)
- [The sustain pedal](https://piakno.com/theory/sustain-pedal)
- [Accompaniment patterns](https://piakno.com/theory/accompaniment-patterns)