What's it like to play Ariel? 

It's so exciting understudying a massive part in a ground-breaking production. Before the two shows, I spent a lot of time getting my mind to a place of relaxation. It's important for me to allow myself that time and space.

But yes, I really enjoyed playing the part. The adrenaline kicks in once you’re out there – and actually – it ends up being very relaxing. 

...And being across from Simon Russell Beale as Prospero means you know you’re in safe hands anyway!

What’s it like working alongside Simon?

Surreal. I remember seeing him in plays when I was at drama school and thinking, “man, this guy is incredible.” And yet, a few years later to be on stage with him is really quite – yeah – surreal. He is an incredible force on stage.

What is your favourite song to perform, and what’s it like performing in front of a full auditorium at the Barbican?

My favourite song to perform is Full Fathom Five, and I've never sung in front of a bigger audience than the one at the Barbican. 

The strange thing is, no matter how often people say they enjoy hearing your voice, it’s never easy hearing it back yourself, for me that is. Plus, you’ve got a live band and you’re having to keep in time with them, so I’d be lying if I didn’t say it was a little nerve wracking...

Anything out of the ordinary happen?

Yes!

I was getting ready to come on stage to bring the lords on in the last act when my mic came out of my wig. It was a bit of a panic for a moment because I knew I wouldn't have another opportunity to get off stage before the final song "Bee Sucks". The mic had to be readjusted at literally the last minute. Normally it goes inside the wig, but on this occasion, they had to clip it onto my hair.

Thank you to all the dressers and sound who made it work!

How long did you have to work on the part?

Greg Doran thought it best that the technology should not be brought in until later in the rehearsal process because the focus should primarily be on the text and the story at the start – the technology shouldn’t distract.

To forge the relationship with the avatar, I stepped in, and Simon spoke his lines directly to me – Mark stood slightly further back doing his own movement and dialogue and once I had learnt it, I would synchronize my movement to his to give a sense of him puppeteering the avatar. 

I guess you can say I worked on the part during the rehearsal process, right up until the tech. Everyone was learning exactly how the avatar worked in the theatre so I had to be aware of any changes in case I ever needed to go on as Ariel.

Is there anything particular about the way the RSC works with understudies?

I feel like the RSC make sure all the understudies have as much rehearsal time as they need so that they can be ready to go on whenever. They really do look after you here, and they treat you just as importantly as anyone else.

The integrity of the show is still on the line, and you have to do the job. Understudying is where you learn, and where many established RSC actors have done so. 

Is there a future in motion capture on stage?

I certainly think there is. This is the first time, so no doubt there will be improvements. I’m sure there will be companies who, having seen this, have thought: “we might have a go at that…”

Any tips for aspiring actors?

Read as much as you can. Go watch as much as you can. And just practise. You can rehearse Shakespeare at home, so pick a speech and practise. The more you do it, the more confident you’ll be.

Can you sum up your experience on The Tempest in a few words?

Exciting, educational, thrilling and rewarding - I’m glad I came on board with this. To study a part like this, for the RSC, you can’t do it and not gain something from it.

Caleb Frederick plays a Spirit and Mariner in The Tempest playing at the Barbican until 18 August. Tickets are available through the Barbican Box Office, online or over the phone: 020 7638 8891.