He obtained the first prize for double bass and chamber music at the Royal Conservatory at Liège, Belgium. He has worked extensively as a classical musician, playing concerts and making recordings with the Radio Symphonic Orchestra, the National Brussel's Orchestra, the Philharmonic Orchestra from Liège and the Opéra Royal de Wallonie.

As a Jazz musician, he has taken part in a number of seminars (with Jean-Louis Rassinfosse, Steve Houben, Charles Loos and John Clayton) and has appeared with Jacques Pelzer, Jean-Pierre Catoul and others.

He is regularly involved with the major educational project in Belgium, Les Jeunesses Musicales. He is teaching and performing a lot of Bass Workshops, Seminars and Master Class.

He has also, from 1986 till 2005, been bass soloist with the ensemble of the French singer and songwriter William Sheller. In 2000, André Klenes founded "Adam’s Dream", first as a string quintet, as the cello and bass duo, and recently as The Strings Trio & Drums; he produced and recorded 5 albums with this project for Chamber/AMG.

In 2006, he recorded the album « Colours of Turner» with the finger-style guitar player Jacques Stotzem. Late 2006, he created a concept album : "Ballade sur le nom de Rimbaud for the Arthur Rimbaud Museum in Charleville-Mezières (France) ".

In 2007 he joined JassTango Quartet in DE, and in 2008 recorded with this band an album by Topaz-Köln.

2009 : Album for Strings Trio & Drums : Moonly Delights (Chamber/AMG). 2010,« Live at Marni Theater ».

2011 : Music for the Tulsa Ballet (US) on a choreography by Tony Fabre.

He becomes a part of the project « Music 4 a While » with Johan Dupont, pn / Muriel Bruno, voc / Jean-François Foliez, clar / Joachim Iannello, vl.

2012 : Laureate of the RVH Bass Trophy (Sheraton Brussels).

2013 : Harmony-Jazz-Suite for jazz quartet and harmony orchestra created at Jazz-Maastricht-Festival.

Music 4 a While first album and tour.