Many performance styles are primarily focused on the voice and what it does with the rhythm and notes of a song . Opera comes to mind where it's original intent was to dazzle an audience with vocal skill and prowess. Pop music today is more about vocal acrobatics and less about the lyrics. What these two genres have in common is "showing off" the vocals. With Musical Theater and Cabaret performing, the emphasis is really on the story and the story telling.
A good theater performer's goal is always to "be" the character and tell his/her story. It's not about how great they sound, it's not a self conscious effort, the focus is on emotion, motivation, the desire to reveal and share feeling. It is no different than an acting moment, actually it IS one, just set to notes and rhythm. That is what is so exciting to me: the opportunity to combine music and acting in one moment. AND what I have found ironic through the years of performing is this: when you concentrate on telling your story in the most authentic and heart to heart way, the on-looker or listener will experience your voice is beautiful. Why? Because you have touched them, you have connected with them and THAT makes their experience with you a beautiful one.
Those specifically trained to be Musical Theater performers learn that THEY are not the star of the song, they are the messenger of the story, the music and lyrics are the star. Their job is to share the emotional content of the moment with their "partner" on stage and an audience. If and when an audience is moved by that moment, the actor has more than succeeded. This holds true equally with Cabaret performing.
One of the prime aspects of performing of which I remind myself and my students is this very point. I will often point out to them the performers who are self-conscious versus those whose focus is on the emotional content. Simply put, it's the difference between "Listen to me" versus "Listen to this"...
A great exercise is to go on YouTube and look at various Theater and Cabaret performers and see if you can tell what the performer's primary focus is...here are some examples of really wonderful singing actors....
On the left is Kate Baldwin in performance as Sandra Bloom and right is young Anton Zetterholm performing in a London Cabaret event.
The magnificent Ben Platt doing a flawless job and in Cabaret is young actress Kelsey Roberts getting great mileage out of this comic song from "She Loves Me".