Five-time Broadway World award-winning Toronto creator and performer Rebecca Perry talks about how in an ever-changing world it's important to remember and celebrate the trailblazing, take-no-prisoners, feminine chutzpah of Judy Garland, Bette Davis, Lucille Ball and Betty Hutton. She celebrates how they used humour to allow them to excel in an industry set against them; nodding to the battle for gender equality being fought in today's Hollywood, Rebecca delicately endorses female empowerment, body positivity, optimism and self-worth.

Most women tend to grow up idolising the women that shaped the decade they grew up in. For me that wasn't the case, in fact, it was four women in the 1930s and 40s. Women introduced to me by my grandmother every Sunday, as we would go through her collection of Old Hollywood VHS tapes – remember those? It was our quality time together. Through her careful selection, four actresses shaped me into who I am today. They made me someone who advocates equality, body positivity and isn't afraid to be themselves - guns blazing! I should mention that it didn't hurt that I also grew up listening to the Spice Girls – but we already know and love them. We don't know as much about these four women, and ultimately, it's why I made a one-woman musical about them. I want to focus the lens further back, so let me set the scene…

Hollywood in the 1930s – a place full of sparkle, big studios and big budgets. But beneath that glitz and glamour it was also a place where women had to advocate for themselves for every step forward that they wanted to take. You had to stick to your guns. That's as true today as it was back then when trailblazers like Bette Davis, Judy Garland, Betty Hutton and Lucille Ball were the icons of the Silver Screen. They didn't give up, they stood up for themselves and for their careers. Their weapons of choice were their own voices and the knowledge of their own talents and abilities. These fights were not small ones either – the results sent ripples through Hollywood, changing it for the better.

Did you know that in Old Hollywood, only women had to sign binding contracts that lasted five years and committed them to one studio at a time, forcing them, for the most part, to accept whatever roles they were given? They didn't get to choose them, and it didn't matter whether it would be a positive move in their careers or not. One of the best examples of sticking to your guns was when Bette Davis was offered the lead role in the film adaption Of Human Bondage by RKO Pictures – and she fought Jack Warner (of Warner Bros.) tooth and nail until he released her to do the movie – one of the most defining roles of her career. It also made her the first woman to legally challenge these kinds of contracts. That's huge.

Judy Garland is another example of someone who had their work cut out for them. She did not fit the Hollywood stereotypical image of an ingénue. She was only five feet tall and had a curvature of the spine – often teased as a 'hunchback' by Louis B. Mayer himself. That did not stop her from stepping into the ruby slippers and blowing us all away in The Wizard of Oz. Can you just imagine the kind of optimism it would have taken to keep going when everyone is telling you you're not right for something? But with every move forward, Judy also helped the women of Hollywood, reminding us that talent will always outweigh the obnoxious opinions of a shortsighted studio head. She had a voice and presence you simply couldn't ignore or dismiss.

Betty Hutton became the first character actor and comedienne to be a leading lady in the movies. Annie Get Your Gun was a huge hit and a breakout role for her, its success helped her create a place for women who weren't the ingénue, to be seen as more than just a sidekick. With her skilled clowning, this funny woman made room for the representation of comedic female talent. All of a sudden, Hollywood couldn't get enough of leading ladies who were funny!

Lucille Ball has the most firsts of all of these women – something I examine in more detail in the show. Like Betty, not only did she bulldoze the way for funny females everywhere, she also did things on camera that had never been done before (like publicly talking down to her husband, or acting while pregnant), and she was a pioneer of the visual media. She was also the first female studio owner, and that was a huge step forward for women in the industry. Finally, there was a woman in Hollywood who had authority (to give you an example of the wide-reaching impact that could have, she was responsible for the production of the original Star Trek going ahead!). She was even the first studio head to actively cast 'outside the box', getting the ball rolling on the movement of body positivity that is continuing today.

Their successes made a difference, and not just in Hollywood. Seeing these women on screen or as heads of studios, being powerful, funny, determined, and grounded instead of just 'sitting pretty' is something that helped every kind of woman have self-worth. The public wanted women who had their own personalities and were more than the constructed 'ideal', chosen by a select few studio fat cats. It is important that these four women not be lost to history's pages. There is much that we can learn from them, and their incredible perseverance as they overcame the obstacles they faced with chutzpah, verve and style.

From Judy to Bette, Guilded Balloon Patter Hoose, until 26 Aug (not 7, 14 or 21), 7.30pm, £10 (£9).