top of page


Fiona Choi

Stage: Torch The Place (MTC), Golden Shield (MTC), Dragon Lady: The Many Lives & Deaths of Anna May Wong (2019 Adelaide Cabaret Festival)

Television: The Family Law (SBS), The Letdown (ABC), Mustangs FC (ABC)

Aussie Musicals: Mamma Mia! (Littlestar/Dainty), RENT (Cameron Mackintosh)

Geoff is a wonderful coach – he has such a beautiful way of instilling confidence whilst challenging you to go further. He is genuinely interested and invested in unveiling who you are as an artist. 

I love how he can dissect, pinpoint & guide you through exactly how a particular phrasing or note can be refined to enhance your musicality & storytelling – the results are immediate every time. He understands vocal technique so can offer exercises/tools tailored to marry your voice to the specific demands of whichever song you’re working on.

Geoff is a brilliant musician with an encyclopedic knowledge of musical theatre repertoire, as well as an intimate understanding of what a panel will (& won’t) be looking for in an audition room – this makes him the perfect mentor to build a comprehensive & unique Book with. 

Plus he's just a delightful person to spend time with - I always leave my sessions infused with joy & creativity.

John O'Hara

School of Rock, Wicked, Cats, Priscilla - Queen of the Desert, The Rocky Horror Show, Rock of Ages and The Boy From Oz

Having first worked with Geoff as my musical director on Songs For A New World in 2016, I found his approach to the difficult material detailed, supportive and perhaps most importantly, effective. He had me singing safely and confidently in a way I had not experienced before and my own self awareness around my instrument was significantly extended. Since then I have worked with him on several projects and I see him for repertoire coaching regularly. Geoff’s understanding and knowledge of the voice, but also of musical theatre history is extensive. His enthusiasm around style, thinking outside the square and successful auditioning techniques have helped in my overall approach to how I present myself both as an artist and singer.

Danielle O'Malley

The Secret Garden (OA/GFO), Charlie and the Chocolate Factory (GFO), You're My World - The Cilla Black Story, Antarctica (Tasmanian Theatre Company), South Pacific (OA/GFO), First Date (Pursued By Bear)

I have always carried my rep book with a lot of pride. It's something I have invested a lot of my own time into developing. Then I worked with Geoffrey Castles and realised what a solid audition book ACTUALLY looks like. Thanks to Geoffrey, for at least the next 5 years I have material prepared for almost any audition situation. In this crazy, competitive biz, it's so important to armer yourself with any element of control you can - and what material you take into the room with you, and how prepared you are with that material, is so important. After working with Geoffrey, I can now enter my next audition knowing that I am prepared for anything the musical director may throw my way and the sense of control that has given me is invaluable. 

Trent Sinclair

QLD Conservatorium Graduate 2019, 100 Years Of The History Of Dance

When you’re busy working in the industry or your focus is securing an agent at the end of your bachelor’s degree it can be very easy to forget the importance of your audition book. And when it comes time to audition you find yourself dusting off old songs that are overdone or that you sung a hundred times at Uni. For me, my audition book was filled with songs that I’ve had bad experiences with because of both these reasons. 


I approached Geoff for help in rebuilding my audition book, which now has 16 fresh songs that will fit any brief. Geoff’s knowledge of repertoire and industry expectations is second to none and something you will rarely come across. He offers years of experience as a sought after Musical Director in the industry and imparts all that experience in his coaching. As a student, Geoff expects you to work hard but will, in return, work twice as hard for you. I’m so grateful for the coaching Geoff has provided me with and I couldn’t recommend him more.

Sophie Weiss

Frozen, School Of Rock, The Wizard Of Oz, The Sound Of Music, Dirty Rotten Scoundrels

I have been working with Geoff to assemble a new repertoire folder that reflects who I am and the roles I want to play. His INCREDIBLE wealth of knowledge on rep, in conjunction with his experience as an MD, has been invaluable in helping me create a folder that I can now step into an audition room with confidence and will always feel prepared. My only regret is that I didn't do this with him five years earlier! 

Tom Kantor

VCA Graduate 2019

Geoff works with you to create a book of repertoire that is tailored, original and comprehensive. He has a wealth of music theatre expertise, with a holistic knowledge of the canon and insights as a music director from behind the audition panel. He provided a template and program of guided research, with recommendations and exclusions, to curate a list of songs that suit me as a performer, showcase my strengths, cover stylistic bases, and that I love to sing. Geoff transposed material to highlight my range, re-arranged problematic sheet-music, provided coherent and timely audition cuts, and recorded backings for practice. As a recent drama-school graduate, working with Geoff has been a joyous, challenging and informative masterclass, in the machinations of the industry as well as in the compilation of repertoire. I now feel incredibly well-equipped, prepared, confident and reflected as a performer walking into the audition room with my material.

Mia Dabkowski-Chandler

9 to 5 The Musical, Jersey Boys, Aladdin, Thoroughly Modern Millie, Ragtime

Having first worked with Geoff in 2016 on Aladdin, marking my professional debut, made what was one of the most rewarding tours of my career thus far. In the two years I worked with him as my Musical Director I learnt more than just how to perform eight shows a week but also the bravery that comes with carrying a show through cities, maintaining cast alignment, principles and work ethic. Since then I have had the opportunity to work with Geoff to rebuild my repertoire book from the ground up. His level of insight directed me to find songs that genuinely reflect who I am, what I want to say and how I want to be perceived. For many years I had the same few songs I would fluke my way through auditions with and I am so excited and ready to get back in the room with this new book we have compiled. I am more confident, excited and motivated to sing these songs. Geoff’s approach to developing and directing your instrument and book should be envied. With grace, perspective, knowledge, experience and healthy industry expectations - he helps you navigate through material, provides honest feedback and transposes, cuts and re-arranges the music to tailor to your needs as an artist. I usually don’t enjoy finding audition songs and am anxiety riddled but Geoff has turned the feeling into empowerment. Class act! 

Grady Swithenbank

QLD Conservatorium Grad 2017, The Bridges Of Madison County

I first started working with Geoff on Bridges of Madison County. This experience was truly something special which Geoff was absolutely a primal factor in creating. The passion Geoff has for the craft of Musical Theatre as well as his respect for all the disciplines that are involved in the story telling of the artform is unlike any other Musical Director I’ve worked with. It is an absolute privilege being able to work with this man and I am very grateful that I had the opportunity to work with him on my Audition Portfolio. His knowledge, leadership and insane work-ethic helped me build a Rep Book that shows what I have to offer as a performer, whilst bringing an excitement and hunger towards performing them in future auditions. I highly recommend working with Geoff, he’s one in a million!

Samuel Skuthorp

Sweeney Todd, The Beautiful Game, Melba

I have always really enjoyed discovering repertoire and preparing for auditions. However, this led me to having an overflowing audition book that didn't necessarily reflect who I was as a performer. 

Working with Geoff is an invaluable experience. He has a tremendous knowledge of music that helps you expand and then condense your audition book to a solid and versatile list of songs.

Geoff knows exactly what creative panels are looking for, and he guides you making smart choices that not only reflect you, but also encompass what the panel wants to hear. Geoff goes above and beyond working with you - researching, suggesting, transposing, rearranging and cutting music so it highlights YOUR unique vocal abilities.

After working with Geoff I feel solid in my book and confident walking into any audition room. I can not recommend working with Geoff enough.

Monique Warren

WAAPA Graduate 2017, Dirty Dancing: The Immersive Experience

It has been invigorating developing my audition book with Geoff. With his coaching I have broadened my repertoire knowledge and refined my artistic tastes. It was a little scary at the beginning of the process to realise that most of the songs I had been using in auditions hadn't been serving me. However his methodical approach challenged me to find music that I love and reflects the kind of performer I am and want to be. This in turn has focused my practice. With a rep book I am now so proud of, I cannot wait to get back into the audition room and try out my new songs! His wealth of knowledge and generosity has been integral in helping me stay motivated. It has been a joy working with Geoff.

Alex Rathgeber

The Phantom of the Opera (West End), Anything Goes, The Wizard of Oz, Ghost, The Boy From Oz, The Rocky Horror Show, The Drowsy Chaperone, Jekyll & Hyde 25th Anniversary Concert

As a singer, I know I'm quite often my own harshest critic, so it's been a real gift to work with Geoff and receive his unwavering encouragement and support. He's not only reminded me to carefully examine and excavate the text and the notes on the page, he's also reminded me to trust and lean into my own instincts and to have faith in my abilities. 

With Geoff's considered, expert assistance, I chose a range of repertoire that I knew would challenge and extend me - some of which I'd previously felt a little afraid to tackle. With each lesson, Geoff guided me to rediscover the joy of studying the character, context, period, style, and overall feeling of each piece and the world of the story it lives in. Geoff's really helped me enhance my own way of interpreting the material, feeling a strong sense of ownership of the music, as well as greater command of my own voice. 

I've absolutely loved the process of absorbing and applying Geoff's insightful perspective as we've worked together on each piece. Geoff has inspired me to keep delving into why each composer & lyricist might make the choices they do, and how I might be able to express their intentions differently every time I approach any given song, to breathe new life into it and bring it truly alive for myself, and thereby for the audience. 

Gillian Cosgriff

Harry Potter and the Cursed Child, Vivid White (MTC), Loving Repeating (Vic Theatre Company), Adelaide Cabaret Festival, Edinburgh Fringe Festival, Melbourne International Comedy Festival.

The work I have done with Geoff Castles has been invaluable. We worked to curate an audition book of songs that cover a multitude of vocal styles, genres, and characters, and most importantly, that I love to sing. Providing each song in full as well as creating an audition cut means that I’ve never felt more prepared for any audition situation. His knowledge, patience, and attention to detail (combined with his sheer love of music theatre) made this task not only painless, but incredibly enjoyable. Geoff’s approach is immensely beneficial because he considers the individual, looking at your specific skill set and capabilities, and aims to fill the gaps in your knowledge and repertoire.  More than all this though, Geoff made me fall back in love with music theatre. He encouraged me to examine my place in this art form – where my career might lead me and what I might need to work on to get there – and it is this that I am most grateful for.

Francine Cain

2010 Rob Guest Endowment Winner, Rock Of Ages, Grease, Chitty Chitty Bang Bang, The Play That Goes Wrong, Peter Pan Goes Wrong.

Working with Geoff was an extremely wonderful and enlightening experience. His vast knowledge of the industry helped me build a unique and diverse range of songs that I know will help me shine in the audition room. Geoff was also able to see in me certain characters and style choices that I hadn't even considered before as well as introducing to me songs and shows I'd never even heard of. After 3 months working with Geoff I feel like a brand new performer! 

bottom of page