1-4 · Some Basic Terminology

A quick, no-memorization tour of the words the course leans on: pitch class, interval, scale, chord, arpeggio, tonal center, and root. The one distinction worth catching now is root vs. tonal center — a root is local (the note a given chord or scale is named from), while a tonal center is global (the "home" note a whole passage pulls toward). Nothing to drill here — just enough shared vocabulary so the lessons ahead land cleanly.

A few music-theory terms come up throughout the course. There’s nothing to memorize here. The goal is just to be familiar enough with the ideas that the upcoming lessons make sense.

• Pitch: How high or low a note sounds. Move along one string and each fret gives you a slightly higher pitch.
• Octave: Twelve frets (semitones) above any note, you’re back at essentially the same note, just higher. That relationship is an octave. The word can also refer to a span of pitches ranging up to 12 semitones.
• Pitch class: Notes an octave apart sound similar in a deep way, and that shared identity is their pitch class, the musical “color” of the note. We give pitch classes letter names like A, B♭, or C#, and there are twelve of them in Western music. Everything in this course (scales, chords, intervals) is defined by relationships between pitch classes, not by how high or low the notes are. I’ll often say “note” when I mean pitch class, because it’s shorter; when I do, it doesn’t matter what octave the note is in.
• Chromatic scale: The scale that includes all twelve pitch classes.
• Semitone: An interval equivalent to a one-fret distance on guitar, and the smallest interval in Western music theory.
• Interval: The distance between two notes, using one note as a reference and counting the semitones it takes to reach the other. Because we ignore the octave, there are twelve possible interval distances, and each has its own sound. Intervals shape the sound of scales, define the structure of chords, and describe how melodies move. We’ll go much deeper into them later in the course.
• Scale: A collection of pitch classes. Most common scales have five or seven notes, and this course also uses a few six-note scales. The intervals between the notes are what give each scale its characteristic sound.
• Tonal center: The “home base” note in a musical context, the pitch class everything else feels drawn toward. It usually corresponds to the key of the piece. Scale practice traditionally starts and ends on the tonal center, which reinforces the sound of the scale but, as we’ll see, isn’t necessarily the best way to practice. Throughout the course, we’ll use a drone or a sustained chord to make the tonal center obvious, which is much better for training your ears.
• Chord: Two or more pitch classes played together. Most chords have three or four notes. Chords provide the harmonic context that scales sit on top of, and many of the chords we use most are built right into the scales themselves.
• Arpeggio: A chord played one note at a time over one or more octaves. Arpeggios show up constantly in solos and melodies, whether you recognize them or not, because outlining harmony directly is one of the quickest ways to sound melodic. Later in the course I’ll show you how to see arpeggios inside a scale, so you won’t need to memorize them as separate patterns.