Music Theory Essentials for Audio Engineers

While you don't have to be a musician or composer, knowing a few essential aspects of Music Theory can make you a better Audio Engineer. 

If you plan on working in, and around, the world of Music Production, it helps to understand a few key elements of Music Theory. While some engineers are pretty good musicians in their own right, you don't have to be a virtuoso musician, or composer, to be an audio engineer. However, knowing a few basic elements of music can help you with communication and workflow, also technical work such as tuning vocals, tempo based fx, navigation, etc... We are here to serve our client (musicians & producers) needs, and a better understanding of what they are trying to achieve will help you as much as it helps them. Let's take a look at how music theory concepts are applied to a Pro Tools session from the audio engineer's point of view.

Beats

Beats form the basis of Musical Time. Think of Beats as the steady pulse of music, ex: 1, 2, 3, 4 - 1, 2, 3, 4, or 1, 2, 3 - 1, 2, 3

Tempo

The number of Beats per Minute gives us our Tempo. Tempo is basically the "speed" of the music being played.
In every piece of equipment, including Pro Tools, the default Tempo for a session is 120 Beats per Minute (bpm). Pro Tools gives you the ability to add Tempo changes into a Ruler at the top of the Edit Window. You can add as many Tempo events as you want, depending on the needs of the music. Usually, the Musicians, or Producer, will tell you what Tempo they will be working at. It is up to you as the Audio Engineer to document this for your future benefit.

Add Tempo Change Window

To add a Tempo Change in Pro Tools, click the "+" button in the Tempo Ruler (Edit Window). Once you have your Tempo Change window up, type in a Location, and Tempo value. You can keep on doing this as necessary if the song requires multiple tempo changes over time.
One of the thing you'll notice when adding a tempo change to your session is that the Grid lines representing Bars | Beats will change their spacing. They will be further apart for a slower tempo, and closer togerther with a faster tempo.

Measure

Also known as a Bar, it is a grouping of Beats consisting of Accented and Unaccented pulses. A Measure is indicated by Bar Lines. An example would be | 1 2 3 4 | 1 2 3 4 | 1 2 3 4 | etc... Each mesure containts a certain number of Beats within it, in our example, there are 4 Beats per measure.

Meter (Time Signature)

The number of Beats per Measure, generally grouped into patterns of 2, 3, 4 or more. Meter is represented in music as 2 numbers at the beginning of a composition.

The upper digit indicates the number of note values per measure, the lower digit indicates the note value. In our example above, we are dealing with 4 in the time of 4. This is the most common Meter for western music. Think to yourself: 1 2 3 4, 1 2 3 4, 1 2 3 4 - this is a Meter of 4/4. Music allows you to work in alternate meter's, such as 3/4 time. In this case your measure would count: 1 2 3, 1 2 3, 1 2 3, due to the fact that the meter is telling us 3 beats in the time of 4.

You can see the how these different meters affect your view in Pro Tools below.

Grid lines represent Meter of 4/4

The pic above shows you how your Grid Lines will look with a Meter of 4/4. Notice the solid blue lines, these are Measures. The ghost lines between them represent the current Meter. There are 4 part in the measure: 4 in the time of 4

Grid lines represent a Meter of 3/4

In this example our Meter is set to 3/4. Notice how we only have 3 parts per measure as opposed to 4. Again, this is a result of the Meter change of 3 in the time of 4.

Grid Value Display Selector

In Pro Tools you can change how many Bar | Beat lines you are seeing per measure. At the top of the Edit Window there is a Grid Selector. This allows you to change the grid division of each measure from Whole notes, to 1/2 notes, 1/4 notes, etc..., all the way down to 1/64 notes. These Grid lines will always match the Tempo and Meter of the session. For example, in a meter of 4/4 you will have 4 parts per measure when you select 1/4 note, while in 3/4 Meter you will have 3 parts per measure when you select 1/4 note Grid.

The benefit of working in Grid mode is that it locks all your movements and edits to the grid lines. Since the Grid is an exact representation of your Tempo and Meter, all you edits can be in perfect timing with the song.

Song Structure

No matter how long, or complex, songs are a collection of measures. The measures are usually grouped together into sections called Verse, Chorus, Bridge, etc... In standard western music, a song usually consists of Verse 1, Chorus 1, Verse 2 Chorus 2, Bridge, Chorus 3. There are obviously many ways a song can be structured, that is up to the songwriters and composers. However, for the audio engineer, it is helpful to understand this terminology because this is how your clients speak to each other. The will usually say something like: "Can you go back to Chorus 1" or "Let's begin the top of Verse 2".
It is extremely helpful to label these parts of the song so you can navigate quickly when asked. In Pro Tools you can use the Markers Ruler to lay out your song structure. By clicking the "+" button in the Marker Ruler (or pressing the Enter Key on the numeric keypad) you will get the New Memory Locations window. This allows you to select a Marker and give it a name.

Add Marker/Memory Location Window

By adding these markers you can easily identify the sections of the song. The example below shows you what it might look like.

Markers displayed on Marker Ruler

You can use the Markers to navigate within the session. If you click on a Marker, it will move your cursor to that position in time. Markers can also be repositioned if necessary simply by clicking and dragging them in the ruler.

Quantize

While not really a music theory concept, Quantize if a feature of DAW's most musicians will ask an engineer to use. Quantize is a feature of all DAW's and sequencers which allows you to move a selection of musical notes so they are on time with the Bars and Beats of the song. Often times thought of as a MIDI concept, Quantize allows you to fix imperfect timing of a musical recording. It allows you to shift a  musical part that was played off-time to be back in groove with the rest of the music. In Pro Tools, you have the ability to Quantize MIDI notes (music notes), as well as Audio Events.
Quantize is generally utilized during the recording/production stages when working with musicians. As you already know, humans are imperfect, which means that sometimes the parts being played are ok, but not really locked in time with the other elements. Usually this is a result of performing the notes late, or early, something usually referred to as "timing". 

As we've mentioned, Quantize can be found in all DAW's, as well as music composition software such as Sibelius, or Finale.
To use Quantize in Pro Tools, go to the Event Menu, select the sub-menu called Event Operation, Quantize. Then you must select the MIDI notes you wish to apply the Quantization function, as well as choosing you variables.

Quantize Window

The main things you should pay attention to are "What To Quantize", which is asking you to decide which part of the note to move to the nearest Beat, the beginning of the note, or the end. Musically speaking, you would want to Quantize the beginning of the note by selecting the "Note On" option. (Many DAW's automatically assume you will quantize the note beginning)
Then you must select your Quantization Grid, which will tell the notes which nearest Beat to move to. This will depend on the complexity of the part being played. For example: If the musician is playing a simple 4 Beat stab, you could easily choose a 1/4 Quantize, and the notes will move to the nearest 1/4 note Grid value. If the musician is playing a complicated pattern with 1/16th notes, you would want to choose a 1/16th Quantize. You will also find that different sections of a song might require you to use different quantize values.

Key Signature Ruler

The arrangement of musical notes, sharps and flats, which indicate the most common pitches in a piece of music. This is quite a hefty concept to wrap your head around, I know. As an audio engineer, this information would be given to you by the songwriter / composer. It's not something you need to pick up on yourself. If you know the Key Signature of the song, it can help you with engineering tasks such as pitch correction with Auto-Tune or Melodyne. Furthermore, musical keys are associated with pitches (frequencies), which we change by using EQ's.

Add Key Signature Change Window

To add a Key Signature change in Pro Tools, click the "+" button in the Key Signature Ruler. The above window will as you which key you want to add, Major or Minor, Sharps or Flats. One of the great things about this feature is that it allows you to transpose an existing arrangement into a different key. This is handy when you're working on a piece of music that was written in a lower register for a male lead, and now needs to be transposed up for a female lead. 

Chords Ruler

By definition, a Chord is a grouping of notes, 2 or more (usually 3), that are played simultaneously. In the context of music production, it generally refers to the movement of notes within a particular Key. For instance: a song can be in the Key of Dmajor, with the Chord progression of G, Bminor, F#minor, Eminor. Once again, these changes would generally be told to the audio engineer by the songwriter or composer. You can add these changes to your Pro Tools session by clicking the "+" button in the Chords Ruler. In the dialogue window that pops up you can select any type of Chord necessary, from Major and Minor, to 7 #9 #11, aug 7 #9, and any other chord the songwriters heart desires. 

Add Chord Change Window

For all of you guitar players, the Chord Change window also allows you to designate which Chord position to use at that change.

 
Pro Tools session displaying all music data 

While not necessary for every audio engineer to know all these things, it helps a lot, especially for those working in a music studio. Post Production engineers dealing with film or TV don't have to worry about the Tempo, Meter, or Key Signature Rulers. By taking the time to study and understand these concepts it not only will make your workflow much smoother, you might find that you like writing music as well. That's what happened to me.