Marlen Bieber was a member of the newly founded opera studio at Chemnitz Opera during the 2020/21 season. Since 2021/22, she has been a soloist at the theater and has appeared as Muse/Niklas in THE TALES OF HOFFMANN, Prince Orlofsky in DIE FLEDERMAUS, Flora and Annina in LA TRAVIATA, Mercédès in CARMEN, Maddalena in RIGOLETTO, and Hansel in HANSEL AND GRETEL. She also played Hänsel in the DVD recording released by Die Theater Chemnitz in collaboration with Rondeau Productions in 2021. In 2022, Bieber made her debut as Lišák (Fox Goldmane) in PŘÍHODY LIŠKY BYSTROUŠKY (The Cunning Little Vixen) in Chemnitz and guest starred in the same role at the Musiktheater im Revier in Gelsenkirchen. During her studies, the mezzo-soprano gained her first stage experience in the university productions DAS SCHLAUE FÜCHSLEIN and LE NOZZE DI FIGARO, where she was heard as Specht and Cherubino. In 2018, she made her debut as the Second Boy (THE MAGIC FLUTE) at the Staatsoperette Dresden. Another great passion of the mezzo-soprano lies in concert singing. During her studies, she regularly performed under the direction of Hans-Christoph Rademann, primarily featuring the cantatas of Johann Sebastian Bach. 
Highlights of her concert activity include her debut at the Dresden Music Festival in 2023 with THE WHITE ROSE by David Chesky. In 2024, she performed as Alto 1 / Mulier Samaritana in Mahler's Symphony No. 8 alongside the Robert Schumann Philharmonic and the Jena Philharmonic. Her collaboration with the Junge Philharmonie Wien led her to appearances at the Millstatt Music Weeks and the Arnold Schoenberg Center in Vienna. In July 2025, she joined the same ensemble, along with the Choir Academy of the Vienna State Opera and the Wilten Boys' Choir, to perform Mahler's Symphony No. 3 at the Gustav Mahler Music Weeks in Toblach. The festival Musique & Vin au Clos Vougeot featured the mezzo-soprano in 2025 as a Jeune Talent in several concerts, including performances with the Orchestre Dijon Bourgogne under Joseph Bastian and in joint appearances with Jean-Yves Thibaudet. In addition to Hans-Christoph Rademann, she has worked with conductors such as Eckehard Stier, Roland Böer, Guillermo García Calvo and Eric Jacobson. Marlen Bieber was awarded with the Eva Kleinitz Award at the Concorso Lirico Internazionale di Portofino 2024. She is a Finalist of the International Robert-Schumann-Competiton 2024 and prize-winner of the DEBUT Classical Singing Competition in 2022. She is a scholarship holder of the Festival of Young Voices and the Richard Wagner Association. She completed her high school diploma in music at the Clara-Wieck-Gymnasium and at the Robert-Schumann-Conservatory in Zwickau. From 2016 to 2021 she studied singing at the Hochschule für Musik in Dresden with Margret Trappe-Wiel and Lothar Odinius. She received further valuable impulses in the Song-class of Olaf Bär and in numerous master classes, among others with Brigitte Fassbaender, Hedwig Fassbender and Jukka Rasilainen. In private lessons she also works closely with the polish soprano Lucja Zarzycka.