Sing as you Like!

When it comes to singing, the vocal folds are in charge of the following:

1. Pitch – How high or low your voice is
2. Compression and Decompression – How close your vocal folds are to each other
3. (Laryngeal) Register – How your vocal folds are vibrating

These combine to create a source signal with a spectral slope that will later be filtered by your vocal tract.

This post is the first in a series of articles discussing the Vocal Folds and their role they play when singing. In this particular article, I will introduce you to a great video on the larynx and explain how we manipulate pitch.

William Vennard: The Vibrating Larynx

One of the best ways to understand how the vocal folds work is to see them in action.

Throughout this post, I will refer to selected timestamps in William Vennard’s medical research film, “Voice Production: The Vibrating Larynx” (The Vibrating Larynx). You may view the entire video here:

In this film, a larynx (which houses the vocal folds) is built up step by step, showing you all the various parts and muscles that make it up. Air is also blown through the vocal folds so you can hear what the vocal folds sound like without a head above them.

In this series, I will only give the anatomical information that is necessary to understand the 3 components (pitch, compression and register). Thus, I may leave things out that you might find important.

If you wish to understand the larynx and vocal folds in depth, I would highly recommend watching the film in full.

Component 1: Pitch

Pitch is controlled by the stretching of the vocal folds. You may think of this as similar to how a guitar string plays higher pitches if you tighten the string.

Practical Structure of the Larynx (For Pitch)

The cricoid cartilage is a ring that goes around the back. See The Vibrating Larynx at 3:20-4:20 to see what it looks like in isolation.

The sides of the gap contain the cricothyroid muscle (to the left and right of the “Middle cricothyroid ligament” that you see in Screenshot 1).

In order to increase our pitch, we contract this muscle, which causes the vocal folds to stretch. How does this work?

How do we stretch the vocal folds?

Let’s have a look at two screenshots from 18:20 and 18:40 of The Vibrating Larynx. I have labelled them and coloured in the important bits.

From Screenshot 2, you can see where the vocal folds attach: To the middle of the thyroid cartilage in the front of the neck, and to the arytenoid cartilages, which sit atop the back of the cricoid ring.

For more information about the arytenoid cartilages, see The Vibrating Larynx at 4:33-6:25.

The thyroid cartilage is labelled in green, the arytenoids in orange, the vocal folds in blue, the cricoid cartilage in yellow, and the cricothyroid muscle in pink.

In Screenshot 3, we can see what happens when we sing higher in pitch. First, we contract the cricothyroid muscle (pink). Assuming we keep the thyroid cartilage still, the cricoid cartilage tilts upwards in the front (yellow). This causes the arytenoids to move backwards (orange), which in turn causes the vocal folds to stretch (blue).

At very high pitches, the thyroid cartilage may also tilt downwards. See Screenshot 4 from The Vibrating Larynx at 18:15 for what that might look like:

The fact that the larynx tilts forward in this way is why you might hear this action being referred to as laryngeal tilting or rocking.

Note that from what we’ve seen here, the height of the larynx as a whole stays the same. This is a distinct motion from raising the entire larynx.

Suboptimal ways to raise pitch

It should be noted that there are other ways to raise your pitch, such as tension from raising the larynx, extrinsic muscle tension or additional breath pressure.

However, using these methods can be detrimental in both a technical and artistic sense.

For example, if we can only increase our pitch by increasing our breath pressure (i.e. pushing volume), we will only be able to sing loud high notes.

As an additional example, you might only be able to raise your pitch by raising your larynx. This tightens the vocal folds and might make it very difficult to sing higher notes. As raising your larynx also changes the quality of the sound to be brighter, you might only be able to sing bright high notes and not have access to darker-sounding high notes.

What about lowering the pitch?

Aside from relaxing the cricothyroid muscle, the pitch may also be lowered by the activation of the thyroarytenoid muscles.

The thyroarytenoid muscles form the body of the vocal folds themselves. As such, if these muscles contract, the vocal folds themselves contract. This causes the vocal folds to be thicker and more relaxed, which lowers the pitch.

Final Thoughts on Pitch

Ultimately, in our technique training, we want to ensure that our pitch changes are coming mainly from the stretch of the vocal folds. If we cannot reach a given pitch with purely the stretch of the vocal folds, we must train our vocal folds to achieve the relevant coordination.

Every other technique (such as increasing breath pressure for loudness or raising the larynx for brightness) will then become add-ons to our artistic palette, as opposed to acting as crutches to reach higher pitches.

This also speaks to the dangers of overemphasizing the breath when teaching singing. While the breath is important in that we could not sing without breath, it is not the primary actor in changing our pitch, and overly relying on the breath to raise our pitch might even be detrimental.

In the next post, we will discuss the concepts of vocal fold compression and decompression, and how helpful they can be to our sound.