To define his work in a nutshell, he likes to quote Kenneth White's formula (cf. Déambulations dans l'espace nomade - Actes Sud, 1995):
"Concrete or abstract? I like the abstract where a memory of substance remains, the concrete which is refined at the borders of the void."
Lionel Marchetti also devotes himself, on stage, in solo, to improvisation (experimental analogical device with various microphones, feedback, radio waves, tape recorder, modified loudspeakers, analogical synthesizers etc.) and with musicians such as Jérôme Noetinger (electronics, tape recorder), Xavier Garcia (electronics), Seijiro Murayama (percussion, voice), Jean-Baptiste Favory (composition, electronics), Emmanuel Holterbach (composition, electronics), Pierre Mottron (en) (voice), Yan Yun (electronics), Carole Rieussec (electronics), Sébastien Églème (violin), Michel Doneda (saxophone), Patrick Charbonnier (trombone), Nicolas Losson (electronics), as well as with the Japanese musician and dancer Yôko Higashi (composition, electronics and butoh dance)
At the same time, Lionel Marchetti pursues a work of poetic writing (cf. La Revue des Ressources, or the review Lampe-tempête) as well as a theoretical approach to musique concrète and the art of the loudspeaker, as a practicing artist of the genre.
His book La musique concrète de Michel Chion (Metamkine, 1998) remains the most noticed - as well as his essay Haut-parleur, voix et miroir... - technical essay in the form of a letter (Entre-deux / Mômeludies éditions / CFMI de Lyon, 2009).
Lionel Marchetti is a composer of concrete music. He works daily in what he likes to call his sound studio on a musical poetics allowed by the use of sound technologies - from analog to digital - from the use of the loudspeaker to the associated recording, up to the acousmatic interpretation, and this, in the line of this specific art.