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Trio O3 is composed by Eugénie Defraigne, Léna Kollmeier and Lydie Thonnard. The trio came to life thanks to the common interest of the three musicians in today's vibrant music.


After having defined their very own universe, the three musicians presented their first project, « Echos de la Terre » in 2017 at the Espace Senghor in Brussels. In 2018, the Trio O3 was the winner of the Supernova Competition, and a year later they won the prize for best interpretation of a contemporary work as well as a third prize at the Opus 2019 international competition.


The trio has performed in several festivals and concert halls in Belgium, such as Flagey in Brussels and the Palais des Beaux-Arts in Charleroi. They have also been invited to the « Ars Musica » festival in November 2020 and to the « Belgian Music Days » in 2022.


Since 2020, the musicians have been promoting Belgian music (premieres of works by Adrien Tsilogiannis, Sarah Wéry, Jonah Blumenthal, Max Charue, Virginie Tasset and Fabian Fiorini) at home and abroad, notably at the Arvo Pärt Center in Estonia as part of the Nargenfestival. Alongside their various trio projects, they collaborate with other musicians such as mezzo-soprano Frauke Elsen, with whom they offer an all-female contemporary repertoire to be presented this October at the LOOP Festival in Brussels.


In November 2022, the Arsonic hall in Mons (Belgium) welcomed the musicians for the recording of their first album, due for release in March 2024.


Born in 1991, Eugénie grew up with music and was very quickly attracted to the cello in particular. She first took cello lessons at the music school in Marche-en-Famenne and then at the “Conservatoire Royal de Musique de Liège” in the class of Jean-Pol Zanutel. During her studies and in the context of multiple masterclasses she had the opportunity to work with several great cellists like Jeanne Maisonhaute, Pieter Wispelwey, Marc Coppey and Philippe Bary. Around the same time she also developed a passion for chamber music following excellent experiences under the supervision of François Deppe, Vincent Royer and Olivier Vanderschagen.

Being generally curious and very interested in contemporary music, Eugénie has collaborated a lot with composers of both her own school and the city of Liège. She also familiarised herself with electro-acoustic music and had the chance to work with the composer Marcin Stanczyck at the IRCAM (Institut de Recherche et Coordination Acoustique) on the occasion of a collaboration with the CNSM in Paris.

With her master’s degree obtained in June 2014, Eugénie performed  during two years with the ensemble Musiques Nouvelles (conducted by Jean-Paul Dessy) in places like the Arsonic theatre, Bozar or the Flagey studios and continues to work with present-day composers in various workshops.

Always on the lookout for new artistic experiences, Eugénie also participates in numerous trainings for free improvisation and jazz, be it for music or dance. This open spirit already made this eclectic musician participate in different shows mixing dance, theatre or poetry...


Her urge for creation manifests itself in her group "Lago" (folk/pop/progressive), which published its first EP “The Spider is Gone” in November 2017 and which just signed with "Roxrecords" Label.

Eugénie also performs chamber music with Trio O3, a contemporary music trio she founded in 2014 alongside Lydie Thonnard and Léna Kollmeier.

In parallel to her activities, Eugénie teaches cello at the “Conservatoire de Ciney”.



Lydie Thonnard is a multi-faceted musician, who has been living in Brussels now for almost 10 years. She has been attracted to music since an early age, and she eventually went to the Royal Conservatory of Liège, where she studied the flute with Toon Fret. During these years, she devoted herself especially to chamber music and developed a taste for improvisation.

Curious and always on the lookout for novelties, she likes to discover and be inspired by new cultures and musical practices. She participated in various projects in Ecuador, Morocco and India, and continued her training with musicians from the world of folk and jazz, such as B.C. Manjunath, Keyvan Chemirani, Efrén López, Henri Tournier, Philippe Laloy, Marie-Sophie Talbot, Manu Hermia, Bo Van der Werf or Raphaëlle Brochet.

She is passionate about rhythm and body percussion and participated in various workshops throughout Europe, notably with Leela Petronio (FR) and Keith Terry (US). She is also a graduate of the Royal Conservatory of Brussels, where she completed a bachelor's degree in "Rhythm and rhythmics" from 2020 to 2023.

Lydie Thonnard plays bass, alto, C and piccolo flutes in various projects, including the duo Auster Loo with Simon Leleux (world/alternative – album: "Rhythm & Breath"), the ensemble Vibrations (flute septet – album: "Strange Meeting") and the Trio O3 (contemporary music & improvisation with electronics). She also sings in the female vocal trio Les chanteuses anonymes and in the project Sans voix en l'air by Olivier Thomas. She has also recorded alongside Michel Massot with Babelouze and Les Surprises du chef.

In parallel to her musical projects, she shares her passion and teaches musical training and the different worldwide practices of musical rhythms in various Brussels academies. She also runs various workshops on voice, creativity and on using the body for rhythms.


Léna Kollmeier, Belgian pianist, mastered her instrument remarkably well at an early age. This naturally led her to being accepted as a young talent by Liège Conservatoire, at the age of 15. She obtained her Master of Arts in piano with honours from Brussels Conservatoire after having studied with teachers such as Daniel Blumenthal, Pierre Thomas and Etienne Rappe. She has also actively participated masterclasses taught by Dominique Cornil, Natacha Zdobnova, Dana Protopopescu and Boyan Vodenitcharov. 

At the age of 17, she won First Prize at the Dexia Classics Competition and performed a recital in the Théâtre Royal de la Monnaie in Brussels which marked the beginning of her career. She soon had the pleasure of performing with various orchestras, and has appeared as a soloist and chamber music specialist on the international stage – namely in Europe, the US, Thailand and the Caribbean in prestigious venues like the Carnegie Hall in New York, the Philharmonie in Luxembourg, El Ateneo in Madrid and the Palacio de Bellas Artes in Santo Domingo. 

Léna Kollmeier is co-founder of two chamber music ensembles: the DUO ROSA, together with soprano Stephany Ortega since 2014, and the Trio O3, specialized in the contemporary repertoire formed with cellist Eugénie Defraigne and flutist Lydie Thonnard. 

The duo launched their first album « Return » in 2016 in the Philharmonie Luxembourg, under the label Etcetera Records. They followed up on their release with a promotional tour - Return World Tour - across 18 cities around the world. In 2019, the duo released their second album « American Soul : from Broadway to Paris » (Hänssler Classic) which has been nominated by the International Classical Music Awards (ICMA) 2020. 

In 2018, the Trio O3 won the « Supernova » competition and allowed them to go on tour to several Belgian festivals and concert halls, especially Flagey in Brussels and the Palais des Beaux-Arts in Charleroi. Léna also has a piano duo with her sister Louise Kollmeier. In 2019, the Kollmeier Sisters won a second prize at the international competition « Grand Prize Virtuoso » and performed at the Concertgebouw in Amsterdam for the occasion.



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