The ‘Bad’ News
There are many factors that determine vocal range that we have no control over. These are primarily physiological in nature, and there’s not a whole lot that can be changed. These include the size, thickness, and symmetry of our vocal folds, as well as the thickness of our mucosa (the protective covering surrounding the primary muscle of the folds). Mucosal thickness has a great deal to do with the relative resilience of one person’s folds over another’s. Some voices – usually those with thicker mucosa – are more capable of withstanding ‘abuse’ than others. For example, gospel singers with huge voices who wail away for hours are genetically better suited to withstand that heavier, more strenuous sound.
A singer’s desire to pursue certain types of repertoire may lead them astray in terms of what their voice is biologically most suited to. While there are safe, healthy ways to work on repertoire that lies outside what one is most suited to, those with a desire to perform are often impatient and try to skip the important first steps in working on this type of material. This can lead to a myriad of other vocal issues.
The Good News
Despite these limiting factors, there are things that you can do to maximize and expand your usable range. Here, I must resort to generalization because the process for expanding range is different for different voice types. I do not simply mean soprano vs. bass, but also subcategories like voice size. In order to fully achieve your goals, I recommend working with a skilled vocal technician.
...But How Do I Do It?
A few general principles apply to vocal function as a whole. Source-filter theory suggests that the voice is made up of three parts – the generator (lungs), the source (the vocal folds) and the filter (everything above the vocal folds; i.e., your head). These three factors are intimately interconnected. Problems stemming from one will often lead to issues with the others. That means that whatever you believe may be the issue could, in reality, be a consequence of something else.
Problems with the generator could have to do with sending too much (uncommon) or not sending enough air (more common). There is a direct relationship between the range in which you wish to sing and the amount of air necessary to create the sound. The global standard for the middle ‘A’ on a piano is 440 Hz, also referred to as ‘cycles per second.’ Your vocal folds are no different. In order to produce those sounds, your folds must impact each other that many times per second. Expecting them to do so without sufficient airflow is like flooring a vehicle with a teaspoon of gasoline. If things are uncomfortable as you reach for higher notes, lack of airflow is a potential culprit.
Another factor leading to a smaller vocal range is excess pressure placed on the source (vocal folds). This pressure often feels as though something is getting ‘stuck’ in the throat. Excessive pressure is often the root cause of other vocal issues as well, such as tongue and jaw tension. If it seems as though you are using more pressure than is necessary (hint: You probably are. It is very common.), the best way to fix the issue is usually through ‘semi-occluded’ exercises such as lip trills and raspberries.
The final puzzle piece is the filter (your throat, head, and mouth). Have you ever felt that your phone’s speakers were too quiet? Somehow placing the phone into a cup or other enclosed space helps increase the volume. Why is that? Physics! The sound waves have an opportunity to combine and strengthen prior to hitting your ears. A poorly tuned filter will cause you to work harder in order to produce the notes you are looking to sing.
Here, sadly, I can provide you with no advice. Even more so than the other information contained in this article, tuning the filter is variable from person to person. However, much like the other two factors, semi-occluded exercises can help! Once again, lip trills to the rescue.
Keep in mind: your voice is a muscle. If you wouldn’t go to the gym, and up your weight by 50 lbs at a time, you shouldn’t stretch your voice faster than is comfortable. Scales and stretching exercises should be done progressively over time.
Focusing on these three factors can be helpful, but in order to avoid going about things inefficiently or even potentially causing harm, work with a voice teacher (as opposed to a coach) who understands how these puzzle pieces interact. Going about things the right way will ensure that you can sing the material that you want with no concerns or fears. Happy singing!