“So, Ya Want Tension, Eh?”
This technique of using pedal point* is a great way to increase the tension in a musical phrase. This strategy is not limited to musical situations that include only diatonic chords but when you see such phrases, you might consider it an invitation if additional tension is called for. Have lots of fun with “trial and error” as you explore this one. It’s pretty potent.
*Pedal point involves the playing of a sustained tone while the harmony above it changes, resulting in a dissonant effect.