Lhoëst studied Piano and Arranging at Berklee College of Music in Boston (USA) with i.a. Herb Pomeroy, John Laporta, Mike Metheny and Ken Pullig. He holds a Master of Jazz Composition and Arranging from the Royal Conservatoire of Brussels (B).
In 1981 he won the first prize at the Jazz Hoeilaart Intern’l Contest in Belgium with the Mika Quartet, with which he subsequently performed at Jazz Middelheim, Brosella Jazz, Festival de Lille, and the Belgrade Jazz Festival. He performed with musicians such as Bart Defoort, Michel Hadzigeorgiou, Jan de Haas, Eric Meelaerts, 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. In 1999 and 2001 he won the jazz composition competition of the Belgian Association of Authors, Publishers and Composers SABAM. Since 2001 he has his own column on jazz theory in the magazine Jazz&mo’, fka Jazzmozaïek. 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 (B), Antwerp (B) and Ghent (B).
He regularly gives guest lectures abroad. He is a jury member at the B-Jazz International Contest – Leuven (B), the former Hoeilaart Intern’l Jazz Contest.