"This was like a 21st-century update of something by a young Leonard Bernstein, brimming with vitality, vibrating with life. Connesson repeatedly built tension with layers of short melodic figures, then released it in brass-heavy fanfare-like bursts. It is a riveting showpiece."
- Toronto Star, 25 october 2007, John Terauds

“An artist fascinated by the lyrical domain as well as the instrumental alchemy of orchestra. Connesson’s music is all rounded and powerful. It produces an instant and lasting emotional effect”
- Classica, David Sanson, 2005

“Guillaume Connesson’s artistic personality shines through in all his work and the audiences love it. The seductiveness of his compositions hits the bull’s eye everytime”
- La Lettre du Musicien, Stéphane Friedérich, 2005

"Connesson’s Une lueur dans l’âge sombre (A glimmer in the age of darkness) must be one of the few orchestral scores inspired by an article in a science journal. But any fear that it would prove dry and formulaic was swiftly dispelled. Its harmonic language is ripely Romantic, and in 20 minutes it packed in more sumptuous melodies than some eminent French composers have managed in a lifetime."
- The Times, 30 September 2005, Richard Morrison

“He is incontestably the most gifted, demanded and versatile composer of his generation in France today. He has found all the hidden secrets of the symphonic orchestra and excels in their use. His music is dreamlike, forever renewing itself and multiplying melodic and rhythmical discoveries”
- La Terrasse, Jean Lukas, 2003

“Connesson the Connoisseur! Techno Parade is a stimulating score (…) which demands extreme precision and an engineered display”
- Libération, August 3, 2002, Eric Dahan

That Supernova is marked by a strong narrative urgency and that there was more than usual excitement in the house when it stampeded to a close. Connesson is barely in this thirties; one suspects the NSO someday will be proud of having presented the first performance of any of his orchestral music in the United States."
- The Washington Post, 3 december 2001, Tim Page

“He loves the orchestra and the opera, film scores and rock music. His music is hedonistic and skilful. He must be heard - urgently”
- Classica, Bertrand Dermoncourt, 2000

“Why is Guillaume Connesson one of the most intriguing composers of his age? Simply because it is almost unbelievable for such a young composer to possess such a great sense of accomplished craftsmanship (…); because contrary to most of today’s composers, Connesson’s art is not limited to an “aesthetic” posture (…); and finally because Guillaume Connesson does not compose scores that are not entirely inspired, respected or masterly.
- Jean-François Zygel, 1998

“The first impression is that of a great talent both in his use of the orchestra and his magnificent sense of tone. Supernova is symbolic of the return to symphonic compositions by a wave of young composers, but in this particular case, what a blast! It is the birth of a classical repertoire…”
- La Lettre du musicien, Jacques Bonnaure, 1997