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For tighter shots the needed Tv to freeze motion gets shorter. Sometimes you must concede that you won't be able to freeze every part of a performer's body with the options available to you (light, lens, camera's high ISO performance limits). In such a case the key thing to remember is to place the face at highest priority. Even if you have to pan a little to track the face during the exposure and blur the entire rest of the scene, it will look better than the rest of the scene sharp but the lead performer's face blurry.
EOS 5D Mark II, EF 70-200mm f/2.8 L IS II @ 200mm, ISO 1600, f/3.2, 1/200 second. (I could have gotten a slightly better result at f/2.8 and 1/250 if I'd been totally on my game!)

For tighter shots the needed Tv to freeze motion gets shorter. Sometimes you must concede that you won't be able to freeze every part of a performer's body with the options available to you (light, lens, camera's high ISO performance limits). In such a case the key thing to remember is to place the face at highest priority. Even if you have to pan a little to track the face during the exposure and blur the entire rest of the scene, it will look better than the rest of the scene sharp but the lead performer's face blurry. 

_{EOS 5D Mark II, EF 70-200mm f/2.8 L IS II @ 200mm, ISO 1600, f/3.2, 1/200 second. (I could have gotten a slightly better result at f/2.8 and 1/250 if I'd been totally on my game!)}

Photography is the art of capturing light. Most theatrical settings don't offer much light to capture and what light there is to capture is changing rapidly and the subjects are usually very animated.

Shot from the orchestra pit during a dance number. EOS 5D Mark II, EF 24-105mm f/4 IS @ 24mm, ISO 1600, f/4, 1/160 second. Shot using Evaluative metering in Av exposure mode with -1 1/3 stop exposure compensation. I timed the shutter when the nearest briefcases were at the apex of their trajectory.

Manual exposure mode with Evaluative metering showing about -1. EOS 5D Mark II, EF 70-200mm f/2.8 L IS II @ 75mm, ISO 1000, f/3.5 (to get enough DoF for the multiple rows of performers), 1/125 second. Timing the up/down movement of the dancers is critical when using such a slow shutter speed. Notice how much blurrier the dancer at the far right is who is out of sync. Manual exposure with Evaluative metering at about -1. EOS 5D Mark II, EF 70-200mm f/2.8 L IS II @ 200mm, ISO 1600, f/2.8 (notice only the front line is in sharp focus), 1/200 second. I'm right on the edge of motion blur at 200mm and 1/200 second even when timing the kick at it's apex. But the faces are sharp and that's what counts the most.

Manual exposure with Evaluative metering at about -1. EOS 5D MArk II, EF 70-200mm f/2.8 L IS II @ 70mm, ISO 1600, f/4, 1/125 second. The performers who are at the apex of their leaps are fairly sharp, those who were a little early or late show motion blur.

Notice that even though the three previous shots of the same production were done using manual exposure the ISO, AV, and Tv combination are different for each shot. Learning your camera's controls enough to adjust ISO, Tv, and Av by touch without moving your eye from the viewfinder is critical to successful theatrical shooting. So is paying careful attention to the light meter and knowing which metering mode you are in and how each metering mode will affect the readings you are seeing.

_{Manual exposure with Evaluative metering at about -1. EOS 5D Mark II, EF 70-200mm f/2.8 L IS II @ 200mm, ISO 1600, f/2.8 (notice only the front line is in sharp focus), 1/200 second. I'm right on the edge of motion blur at 200mm and 1/200 second even when timing the kick at it's apex. But the faces are sharp and that's what counts the most.}

Photography is the art of capturing light. Most theatrical settings don't offer much light to capture and what light there is to capture is changing rapidly and the subjects are usually very animated.

_{Shot from the orchestra pit during a dance number. EOS 5D Mark II, EF 24-105mm f/4 IS @ 24mm, ISO 1600, f/4, 1/160 second. Shot using Evaluative metering in Av exposure mode with -1 1/3 stop exposure compensation. I timed the shutter when the nearest briefcases were at the apex of their trajectory.}

_{Manual exposure mode with Evaluative metering showing about -1. EOS 5D Mark II, EF 70-200mm f/2.8 L IS II @ 75mm, ISO 1000, f/3.5 (to get enough DoF for the multiple rows of performers), 1/125 second. Timing the up/down movement of the dancers is critical when using such a slow shutter speed. Notice how much blurrier the dancer at the far right is who is out of sync.}

_{Manual exposure with Evaluative metering at about -1. EOS 5D Mark II, EF 70-200mm f/2.8 L IS II @ 70mm, ISO 1600, f/4, 1/125 second. The performers who are at the apex of their leaps are fairly sharp, those who were a little early or late show motion blur.}

Notice that even though three of the four shots above of the same production were done using manual exposure the ISO, AV, and Tv combination are different for each shot. Learning your camera's controls enough to adjust ISO, Tv, and Av by touch without moving your eye from the viewfinder is critical to successful theatrical shooting. So is paying careful attention to the light meter and knowing which metering mode you are in and how each metering mode will affect the readings you are seeing.

Shooting raw images so you will have latitude in adjusting color as well as exposure in post-processing is paramount. Having all the raw data from each image available opens so many more possibilities with regard to color, exposure, contrast, etc. than the much more limited information in a jpeg file (please see this answer to the last question linked below for a fuller explanation).

There's another question here that deals with shooting a music concert from a near stage location. I'm having trouble getting sharp pictures while shooting a concert from a press pass location Much of what is said there is applicable in your situation as well.

There are also a few other questions and answers that you might find helpful:
Regarding lenses:
What are appropriate lenses for concert photography?
What kind of filter (if any) should I use when photographing a theater scene? (hint: Lose the filter on the front of your lens!)
Canon 70-200 f2.8 non IS or f4 IS
Regarding metering/exposure issues
What went wrong with this concert photo and what could I have done to make it better?
Blown out blue/red light making photos look out of focus (particularly this answer)

Shooting raw images so you will have latitude in adjusting color as well as exposure in post-processing is paramount. Having all the raw data from each image available opens so many more possibilities with regard to color, exposure, contrast, etc. than the much more limited information in a jpeg file (please see this answer to the last question linked below for a fuller explanation).

There's another question here that deals with shooting a music concert from a near stage location. I'm having trouble getting sharp pictures while shooting a concert from a press pass location Much of what is said there is applicable in your situation as well.

There are also a few other questions and answers that you might find helpful:
Regarding lenses:
What are appropriate lenses for concert photography?
What kind of filter (if any) should I use when photographing a theater scene? (hint: Lose the filter on the front of your lens!)
Canon 70-200 f2.8 non IS or f4 IS
Regarding metering/exposure issues
What went wrong with this concert photo and what could I have done to make it better?
Blown out blue/red light making photos look out of focus (particularly this answer)