Jean-Pierre Dassonville began his musical studies under the guidance  of his father, and completed them at the Royal Conservatories of Mons and Liège (Belgium) in the class of Nico De Marchi. He then He continued his studies with Francis Orval and Claude Maury.

Currently first principal horn of the Orchestra of the Royal Theatre of La Monnaie in Brussels, he has also been soloist with the Harmony Orchestra of the Music of the Guides, the RTBF Symphony Orchestra, and the Flemish Opera Orchestra.

A much sought-after performer on both natural and romantic horn, he has been first horn in prestigious ensembles such as Les Agrémens, Ex Tempore, Il Gardellino, the Muffati, the Cercle d'Harmonie, the Collegium Vocale, BachPlus, The New Baroque Times, the Orchestre des Champs-Élysées under Philippe Hereweghe and the Anima Eterna orchestra. He is also a winner of the International Alpine Horn Competition, another of his passions, in Nendaz, Switzerland. As a chamber musician, both with modern and natural horn, he has participated in the international chamber music festivals of Stavelot and "Resonances" at the Château d'Halloy, in the ensembles of La Monnaie, among others with Antonio Pappano, the Oxalys Ensemble, Kheops, Quartz, Odéon, Soltice, Mengal, Il Gardellino, the Wolf Ensemble, the Concert Bourgeois, the Danel Quartet, in a duo with the fortpianist Guy Van Waas, the Agrémens wind quintet and the pianist Jos Van Immerseel. With all these ensembles he has made countless recordings and videos.

His activity as a soloist has led him to perform with the Orchestre de la Monnaie under the direction of Kasushi Ono, Alain Altinoglu, the Ensemble Orchestral de Bruxelles, the Lyric Orchestra of the Avignon-Provence Region and the Bruocella Orchestra of Brussels. In 2024 he performed Benjamin Britten's Serenade for tenor, horn and strings with the Orchestre de la Monnaie under Alain Altinoglu in Brussels and Colmar.

At the Vire Horn Festival he premiered Roland Schoelinck's concerto, a work he participated in writing and of which he is the dedicatee. He is regularly invited to the Vire Horn Festivals, Avignon, Montreal and Annecy, to Liverpool by the British Horn Society, and to the symposia of the International Horn Society.

He has given master classes, notably at the Epsilon Festival in Saint-Yrieix La Perche, in Anjou as part of the ARAM, at the Vire and Avignon Festivals, at the Pôles Supérieurs in Dijon and Lille, at the Montreal Conservatory, at the University of Montreal, at the University of Seoul, at the Seminar of Early Music in Namur, at the International Academy of Dinant, at the Saint Vaast Summer Academy, at various congresses of the French Horn Association, in Birmingham and Manchester, invited by the British Horn Society to the IHS symposia, where he taught both modern horn and natural horn. He is also invited as a teacher at the Jeune Orchestre Atlantique in Saintes.

The International Horn Society has also recognised him as one of the great representatives of the "European" horn style. In this context, he has given several performances during the annual symposia, including recitals with a 6-valve Adolphe Sax horn.

All these activities have led him to perform in Europe, Japan, Canada, China, Korea, Singapore and the United States. He currently combines his concert activity with that of professor of horn and natural horn at the Royal Conservatory of Brussels.