Are you a musician? Then I promise you know more about music theory than you think that you do.
Music Theory is not math, as many teachers sometimes suggest (unless you're talking about set theory or other post-tonal studies) but more akin to grammar. It's a set of guidelines that generally govern and/or explain how Western music functions, seeing as it functions similarly to other languages, with patterns and supposed restrictions. Of course, rules frequently get broken on purpose. Lately, I’ve come to think of music theory as a way to describe what is going on in a piece of music.
Many of the concepts covered on this blog are fairly straightfoward and many of them are basic enough to be covered in an elementary classroom.
Here I'll break down some of these theoretical terms (used in the study of music in the Western classical tradition) so that they're accessible to anyone interested.
Starting with four areas: general terms, harmonic terms, rhythmic terms, and melodic terms.
Genre: a type of music. Songs within a genre are typically connected to each other because of musical stylistic traits, instrumentation, and/or historical period.
Chord: a group of notes, played either together (block) or separately (arppegiated, etc.). Chords & chord progressions are the basis of harmonic analysis in many forms of music.
Triad: a chord composed of three notes, and the most commonly discussed chord in Western music theory. The four most common types of triad chords are major, minor, diminished and augmented. This page from Rice University gives a pretty decent explanation of how triads are built.
Roman Numeral Chord Symbols: identifies chords corresponding to the order of a scale. In a diatonic major scale, with seven different pitches, the scale degree-based chord breakdown looks like this: I-ii-iii-IV-V-vi-vii(dim)-I. For a more fully explained breakdown, look here.
Chord Progression: the pattern of chords that tend to repeat in a song. In popular music, chord progressions tend to be a little bit more repetitive, and they can range from the most simplistic to much more complicated. The Roman Numeral "Toolkit", as my grad school theory teacher referred to it, can be used to describe a chord progression.
For example, an extremely common cited chord progression is found my favorite song to play on ukulele — The Postal Service's "Such Great Heights" — with the progression notated as I-V-IV-I-V-I. If you’re playing the song in G major, that would mean you’re playing the chords G-D-C-G-D-G.
Cadence: the harmonic movement between two chords often indicating the end of a phrase. Many cadences follow the pattern of V-I or IV-I, especially in popular music, but of course, not all.
Modulation: a fancy word for changing keys, or using new notes to sing/play a melody that has already been played. Think Bon Jovi's "Livin' on a Prayer" or Beyonce’s “Love on Top.” Different types of modulations are explained in a theory-heavy but easy to use chart found here (thanks UTEP!).
Modes: essentially, modes describe the form that a scale takes. A huge amount of Western music is composed in Ionian Mode, which describes a typical diatonic scale. Think of an Ionian Mode scale as "do re mi fa sol la ti do.” As mentioned, a good deal of Western music operates in Ionian Mode and the harmonic functions thereof. However, in this blog, you'll find investigation of popular songs that do not operate in Ionian Mode.
Dorian Mode begins on the second scale degree; "re mi fa so la ti do re". This mode is often used in jazz music, and hence has a lot of crossover into popular music.
Phrygian Mode begins on the third scale degree; "mi fa sol la ti do re mi".
Lydian Mode begins on the fourth scale degree; "fa sol la ti do re mi fa".
Mixolydian Mode begins on the fifth scale degree; "sol la ti do re mi fa sol".
Aeolian Mode (aka natural minor) begins on the sixth scale degree; "la ti do re mi fa sol la"
Locrian Mode begins on the seventh scale degree; "ti do re mi fa sol la ti".
Meter: what dictates the rhythmic feel of of music. Meter is the indication of how many beats are in a measure, how the beats in a measure can be grouped, and how the beats can be subdivided. This is also related to time signatures. Meters referenced here are divided into several categories:
Symmetrical meter refers to meters in which the number of beats in a measure can be divided into two symmetrical parts (time signatures include 4/4, 2/4, 6/8).
Asymmetrical meter refers to meters in which the number of beats cannot be divided equally in half (incl. 3/4, 5/4, 7/8 time).
Simple meter refers to meters in which a single beat can be divided into two subdivisions (incl. 4/4, 3/4, 5/4 time).
Compound meter refers to meters in which a single beat can be divided into three or more subdivisions (incl. 6/8, 7/8, 5/8 time).
Cross-rhythm (aka poly-rhythm): a rhythmic figure that finds itself at odds with the previously indicated meter; e.g. a triplet (compound) eighth note figure in a symmetrical simple meter.
Changing meter (aka mixed meter): any instance in which the meter or even simply the time signature, better known as the grouping of beats, changes, either once (e.g. Blondie's "Heart of Glass") or consistently (e.g. Neko Case's "Middle Cyclone").
Interval: the space between two different pitches. The smallest interval we’ll discuss here is a minor second and the largest interval (within a scale) is an octave. To first determine the number behind an interval, count how many notes the second note is away from the first note (make sure your count includes the first note). Interval qualities are most often referred to as major, minor, or perfect. To determine what an interval is just from hearing it, you have to train your ear. MusicTheory.net has an awesome training tool for this.
Tritone: an interval that is intended to challenge the ear. Sandwiched between a perfect fourth and a perfect fifth, the tritone was once considered the "Devil's Interval.” Now, you can hear it as the opening interval in the theme song for The Simpsons.
Tessitura: the general range of the majority of the notes in a piece or melodic section. Example: in Sinead O'Connor's "Nothing Compares 2 U", the minor sixth on the second repetition of "no-thing" in the chorus is generally outside of the tessitura of the rest of the song, forcing O'Connor to use her head voice and making the interval stand out.
