Now, the challenge for you when bored, is to be curious.
Ask yourself questions.
Watch and listen to everyone.
Are they acting their parts well? What would you do differently?
Are they singing well? How would you want it to sound?
Are they moving well? How would you alter the choreography to fit with the mood and words of the music?
Are their accents authentic? Listen to some recordings of American actors on your headphones and apply the vowel sounds and inflections you hear to some lines in the show.
When the time comes for you to rehearse your part, you might well have a completely different production in your head!
All of that empty time will have been beneficial to you even if you don't realise it yet and one day, it WILL all seep into your work.
Nearly everything one can learn about performance, can be learnt by watching and listening to others, whether better or worse. Get curious not bored.
(Just don't rubbish everyone else's efforts just yet...)
Love from Uncle Colin
PS Who is this Lady Ga-Ga I'm playing with today?...