Sadly, even though critics have praised the performances within the new jukebox musical Monkee Business, it has not saved the show from receiving scathing reviews. But when a performance is spot on, it can lift a piece of theatre to another level. But when the leads are bad, the show can simply limp on by.

I saw two shows this week which featured polar opposites in terms of acting quality. The first was The Wizard of Oz which I first saw at Christmas with Danielle Hope and Michael Crawford. It was a fluffy and bright show - very light but the commitment from the cast left you with a smile on your face. The ensemble, the leads, and the swings treated the material with respect and even though the show plodded slightly - it remained an enjoyable night out. Fast forward to now and Russell Grant as the Wizard cannot act. He also does the annoying mugging to the audience that stars often feel the need to do, which takes them out of character. Don't even get me started on the Strictly homage!

Sophie Evans is sweet as Dorothy but much of the humour is wasted, as she lacks the experience in how to deliver a line. The Wizard of Oz is a family show and remains a fun show. But, it's a shadow of its former self and is likely to close real soon. It's lively enough and the Wicked Witch of the West steals all the scenes but it lacks the energy it used to have.

Onto Master Class which is exactly that, as Tyne Daly shows you how to deliver a performance that is so astonishing - you believe you are watching Maria Callas. The play's structure is not always perfect as it deviates too much and the masterclasses are where the piece really breathes. But Daly is on fire in every single scene. Many in the audience recalled her in Cagney and Lacey - the hit cop show from the 1980s and I have fond memories of this on Friday nights as a kid. But as a stage actress, Tyne knows how to deliver a punch line and the looks she gives the audience speak a thousand words.

Many have criticised the play but the one thing that has emerged is the talent on stage. This gifted actress manages to convey the poignancy and sense of loss that Callas feels; the unrequited love she felt for Aristotle Onassis, the greatest gift she owned- her voice on the wane and the envy at the new talent shining through. She also managed not to deliver a camp turn which could easily turn Callas into a singing Bette Davis. Acting is about what you leave out, as well as what you show the audience. In the UK, we often hold back from giving standing ovations even though we feel compelled to stand up. It's almost as if we don't want to regret standing up. But a great performance compels you to get up. This is exactly what I did yesterday afternoon - I had no choice. I adored Master Class, as Tyne Daly shows all actors how to deliver a nuanced turn and her performance sets the standard.




Master Class continues at the Vaudeville Theatre until 28 April.