When I work with students, one of the quick fixes I use to make singing easier is to have them eliminate their diphthongs. The word out can be modified to “aht,” for example, so that a singer doesn’t have to adjust mouth positions more than necessary. But while this may be a good rule of thumb, it’s not set in stone. One notable exception (and it’s not the only exception!) is for indie pop stylizing.
Let me say first that when I use the term indie, I use it very loosely to refer to one of the current trends in pop/rock away from a belt and toward a softer, folksier sound. The influence of this sound is not restricted to indie music and has widely trickled into mainstream pop.
Diphthongs and Indie Stylizing
To create the indie sound I’m talking about, singers don’t just refrain from eliminating diphthongs. They actually add them in where they weren’t there before. Listen to the way Cat Power sings “want” in her famous “Sea of Love” cover at around 1.02.
She doesn’t sing “wanna” or “want to.” She makes it sound more like “wah-oh-ooh-na.” There are a variety of reasons artists could make this stylistic choice. One is obvious: that this is what other singers in this genre are doing, and so this is what new singers do too to sound more like them. Another less obvious reason is control of resonance. The “ah” sound gets a singer more frontal resonance, while the “oh” sound is somewhere in the middle, and the “ooh” gets a singer more back resonance. The resulting sound is warmer and further back than a lot of typical pop but still with the conversational edge create by the forward-leaning vowels. It also softens the word at the end of a sustain, giving it a contemplative feel.
How to Stylize Your Diphthongs
As with any vocal fringe technique, you don’t want to do this too often, or your song will start to sound like a parody of the style you’re trying to create. But choose a well-placed sustained vowel, and break it, beginning with a forward vowel (like “a” as in cat) and ending in a back vowel (like “ooh.”) If you were to hold out the word say, you might start with “sa,” driving the word forward, and then pull it back to an open “i” (as in kick) that’s rounded into an “ooh.” Play around with different ideas, including front to back vowels and open to close vowels, in order to test different shifts in resonance. Listen to what other singers are doing, and try developing your own style.