Eleven years old, Marleen Casteele started her musical education playing the guitar at the academy for music in Harelbeke with Armand Coeck. Afterwards, she continued studying guitar, chamber music and the theory of harmony at the Royal Conservatory of Ghent. After a few trainings home and abroad with José Thomas and Leo Brouwer, Marleen improved herself at the Royal Conservatory of Brussels and obtained a superior degree for guitar. Marleen Casteele teaches guitar at the Academy for Music, Word and Dance in Ghent and ensemble in Waregem. Since 1996 she's director of 'Alegria', a guitar ensemble of excellent, non-professional guitar players. 'Alegria' has already made several concert trips abroad.
More and more Marleen Casteele presents herself as a composer. She wrote music for guitar solo, e.g. 'Friendly Memories', works for soprano and guitar and a work for marimba and guitar 'Fairytale Wood'. In 2008, she received a 'Special Merit' in the composition competition of Bérben (Italy) for 'Twin Piece', a work she wrote for the guitar duo D'Hoest.