Every song we sing is the sum of two parts: interpretation and technique.

Without interpretation a song is just a pretty melody, and without technique there is no control to deliver that interpretation as powerfully and efficiently as possible to your audience. Think of every song you sing as a coin. Every coin has two sides, and so does every song. The challenge is to spend your coins wisely to ensure the greatest profit for both you and your audience.
The first side of the coin is interpretation. A song doesn’t need interpretation to SOUND nice – technique alone will achieve that – but in order for a song to FEEL nice, it needs thorough and thoughtful interpretation*. Try singing the next song you practice the whole way through, exaggerating the interpretation. Don’t think about anything else (no one listens to you practicing anyway), just FEEL the song as completely as you can. Overdo every tiny aspect of interpretation – go as big as you can. How did that go? It probably didn’t sound particularly nice but I bet it felt good! Hopefully you found a couple of powerful words you’d been skipping over or a tiny pause that emphasizes a particular phrase.
The second side of the coin is technique. Repeat the exercise, this time emphasizing the technique you’ve had drilled into your head for years. Don’t listen to how it sounds, aim for perfect, flawless technique (although it should still sound good if your technique is 100%). What was the result? Did you even know you could achieve vibrato on that top note? Or maybe you had no idea how quietly you could sing that phrase, or how wide you could make that crescendo? 
So, what if a particular phrase is troubling you interpretively? Flip the coin. The same goes for technique. If something isn’t working one way, try the other. This is musical theatre – the genre where you can whisper, shout, use vibrato, not use vibrato – the options are endless. The application of interpretation and technique is flexible; it is up to you to decide which is most successful at every point in the piece. It may change every note (more likely every phrase or line), or it may not change for the entire piece, but everything we do relies on both sides of the coin, even if it may not be obvious at first.
Now, stand the coin on its edge so you can no longer see either individual side: there’s your song. By balancing interpretation with technique you are guaranteed to give your best performance of that song day in, day out. Getting a song perfect won’t happen overnight, and it’s entirely possible that you’ll have to start some songs from scratch, but I promise you it’s worth the effort. As always, practice makes perfect. Vladimir Horowitz (the Grammy Award-winning pianist) said: "If I don’t practice for a day, I know it. If I don’t practice for two days, my wife knows it. If I don’t practice for three days, the world knows it."
Your voice is your currency; remember to spend it wisely. Some days you may want to use a little more of the interpretation side; others, the technique side. That is up to you, as an intelligent performer who is well in tune with their instrument to decide. Just as there are different shapes, colours and sizes of coins, so is there a different coin for every song or situation. Find the right balance for each song so that your coin rests perfectly on edge every time and watch your currency flow.

*For tips on developing interpretations, check out theatrepeople.com.au/prev_website/feature_articles/2010/February/040210_Notsoundlikeidina.htm