Australian/German mezzo soprano Cassandra Seidemann has  featured extensively on both stage and screen. She is a  favourite with audiences having sung throughout Australia,  Asia and New Zealand. 

Recent highlights included Rossweisse in the Singapore  premiere of Die Walküre, and concert appearances in Australia,  New Zealand and Papua New Guinea. In 2022, she sang  Bradamante in National Opera’s production of Alcina and was  soloist with the Queensland Pops Orchestra in their New  Year’s Eve Gala Concerts. 2023 solo appearances included  those with Queensland Baroque, Festival of Voices Hobart and  Messiah with the Tasmanian Symphony Orchestra. She  returned to the TSO in 2024 for Mozart’s Requiem. 2025 sees  Cassandra joining forces with The Sydney Symphony  Orchestra and The Queensland Symphony Orchestra for their  concerts The Art of the Score: The Music of Hans Zimmer. 

In 2017, she was soloist for Opera Under the Stars in Broome,  Western Australia and in Handel’s Messiah for Christchurch  City Choir. Cassandra returned to Opera Queensland in 2018  as Olga in Graeme Murphy’s new production of The Merry  Widow and starred in a Chinese New Year gala concert at the  Sydney Opera House. 
Cassandra graduated with honours from The University of  Queensland with a Bachelor of Music (Opera Performance).  There she performed the title role in Dido and Aeneas as well  as Hansel in Hansel & Gretel. 
She then joined Opera Queensland as part of the Young Artist  Program appearing as 2nd Bridesmaid in The Marriage of Figaro and understudying Hansel in Hansel and Gretel. Her  affiliation with Opera Queensland has continued to the present  day performing and covering the roles of Wowkle in La  fanciulla del West, Countessa Ceprano in Rigoletto, Flora in La  traviata and Kate Pinkerton and Suzuki in Madama Butterfly. 

Other operatic highlights include the title role in Carmen with  the Sydney Philharmonia and appearing in concert with Jeff  Mills, Derrick May and the Melbourne Symphony Orchestra. 

On screen, she has been featured in the Lord Mayor's Carols in  the City, numerous television commercials, was a featured  artist at the Carols in the Domain 2015 to 2020, played the role  of Mary in the short film Jade and in 2024 made her feature  film debut with the character of Kelly in the film Kane.  

Cassandra's musical theatre appearances include Pitti-Sing in  The Mikado, Gwendolen Fairfax in The Importance of Being  Ernest, Tessa in The Gondoliers and Laurey in Oklahoma!   On  the concert stage, she has taken the alto solos in Handel’s  Messiah and Dixit Dominus, Vivaldi’s Gloria, Schubert’s Mass  in A Major, Bach’s Magnificat, Rossini’s Petite Messe  Solennelle and Mozart’s Requiem and Coronation Mass.  

Cassandra was a grant recipient of The Joan Sutherland  Society, a finalist in the Opera Foundation Australia German  Opera Scholarship and a finalist in the Opera Foundation  Australia Lady Fairfax Scholarship.