Concepts
The encyclopedia half of Theory Aide: one idea per article, explained in plain English first, with the real analysis engine embedded where seeing it work beats reading about it. Jargon links to the dictionary. New articles accumulate one at a time.
Pitch and octave
Double any frequency and you land on the same note, higher. Hear the octave melt into one sound, then bend it and hear it argue.
What is a note
A note is a number: how many times per second the air moves. Dial a frequency, watch the wave, and hear it.
The piano roll
Pitch up, time across, length is duration. Live's grid is real notation, and you can already read it.
The circle of fifths
Twelve keys arranged so neighbors differ by one note. Click around the wheel and hear how far from home you are.
Voices
A voice is one continuous line, whether or not anyone is singing. Your bass and your lead are already two of them.
Motion types
Parallel, similar, oblique, contrary: every pair of moving voices is doing one of four things, ranked by independence.
Counterpoint
The craft of keeping simultaneous melodies independent, with the actual Counterpoint Checker running live in your browser.
Roman numerals
Every major key hands you the same seven chords, and numbering them frees a progression from its key. Watch the letters change while the numbers hold still.
Triads
Stack two thirds and you have a chord. Build all four flavors and let the real engine name what you're hearing.
Intervals
The distance between two notes, counted in semitones, heard as a flavor. Taste seven of them with two live tones.
Pentatonic and blues
Drop two notes from the scale and every clash disappears. Roll random phrases over a drone and hear why the box is where phrasing gets learned.
Melody
Steps, leaps, and contour: what makes a sequence of notes feel like a line with a shape instead of a list.
The Math
A note is a number, and consonance is arithmetic. Then twelve fifths refuse to fit inside seven octaves, and the whole system has to cheat to survive.
Organizing time
Hear a rhythm accelerate until it becomes a pitch, then ride the zoom lens from song form all the way down to timbre. It is time slices all the way down.
Modes
Take one set of notes and move the home around it and you get seven moods, the modes. The secret is that the mode lives in the bass, not the scale.
Minor scales
Keep every note of the major scale and just move where home is. That single move is minor, and it is the keyhole into the whole world of modes.
Keys
Pick a scale and one note becomes home. Hear the same melody land, then hang one row short, and feel the gravity.
The major scale
The step pattern most Western music walks on, climbable from any root. Two two one, two two two one.