In 1981 he won the first prize at the Jazz Hoeilaart Intern’l Contest in Belgium with the Mika Quartet, with which he also performed at Jazz Middelheim, Festival de Lille, and the Belgrade Jazz Festival. He performed with musicians such as Bart Defoort, Michel Hadzigeorgiou, Jan de Haas, Eric Meelaerts, Frank Vague, Dieter Limbourg, Evert Verhees, Chaka Khan, and Bart de Nolf. He was MD of singer Demis Roussos, is pianist with the Belgian Swing Jazz Orchestra and regularly performs with his own quartet.
Lhoëst has written compositions and arrangements for a variety of orchestras, including the Limburg Symphony Orchestra and the former big band of the Belgian broadcasting company BRT, conducted by Etienne Verschueren. In 1999 and 2001 he won the jazz composition competition of the Belgian Association of Authors, Publishers and Composers SABAM. Since 2001 he publishes articles on jazz theory in the magazine Jazzmozaïek, since 2017 called Jazzmo’. In 2016 he published his book “Ins en outs van Jazzharmonie”.
Lhoëst taught at, and was successively head of the Jazz departments of the conservatoires of Brussels, Antwerp and Ghent. Currently he teaches jazz harmony, arranging and composition at the Royal Conservatoire of Ghent.
He regularly gives guest lectures abroad, mainly in Italy and Congo. He is a jury member at the B-Jazz International Contest – Leuven (B), the former Hoeilaart Intern’l Jazz Contest.
He has been a board member of Muziekmozaïek (a non-profit organization promoting folk and jazz in Belgium) and of Resonant (a non-profit organization promoting Flemish musical heritage).