What to Watch For
What is it that separates bad acting from good acting from great acting? When you say that someone gave a great performance, what are you responding to?
The first thing to look for is ease. Does an actor look comfortable on stage? Does she look at home, like she really belongs there, free from any traces of self-consciousness or tension? Does he look like he's having fun (even in a drama, great actors know how to play)? Does he have good rapport with his fellow actors?
When you watch Prelude to a Kiss , look for the ease with which Craig Maravich and Haley Rice (who play the romantic leads, Peter and Rita), inhabit their roles. Look for the chemistry between them, and then remember that they met for the first time just 3 weeks ago. See how playful they are, and how little artifice there seems to be.
Look for how Malachy McCourt watches everyone and everything around him with such intensity. Malachy spends a good deal of time on stage just listening. People often make the mistake of thinking that the real acting happens when you're saying your lines. Malachy shows that listening can be at least as compelling as speaking (and it's even more challenging).
Watch how Paul Ugalde and Melissa Lourie (who play Rita's parents) create fully-dimensional characters even though they're only onstage very briefly. And if you saw King Lear (in which they also played a married couple, Goneril and Albany), you'll appreciate how versatile they are. Look for the little details they add (Melissa's odd laugh, for example) that aren't in the script, but add so much texture and humor to their roles.
The best acting looks easy; it looks as if the actors are just on stage talking and behaving the way they would in real life. If you've ever tried acting yourself, you know how difficult it can be to say words that are not your own, in a situation that is completely fabricated, in front of a room full of strangers, in a way that seems natural. That actors can do this without a hint of self-consciousness, so that it doesn't seem like acting at all, is a testament to the great skill involved.
At the same time, while it may look like behavior you might see in real life, remember that in many cases, actors are asked to go through a range of extreme emotions in a few hours that most of us only experience intermittently in the course of our lives.
When you see an actor in a scene that's highly emotional, (anything from fear to anger to sadness to ecstasy to sexual energy) ask yourself whether it feels like the actor is showing you the emotion, or whether it feels like the actor/character is truly experiencing the emotion. The likelihood is that if you sense that the actor is really feeling it, you'll feel it, too. If you get the sense that the actor is just showing it, you may understand what the character is going through, but the emotional impact may not be as strong.
Watch the show with these things in mind, and let me know what you notice.