To return the favor, in September 2005 Jean-Marc Foussat recorded Duboc playing his new program with Didier Lasserre on drums and Sylvain Guérineau on alto/baritone saxophones at the Olympic Café in Paris – the concert was released as [TER] CD by Olympic Café label. Foussat met both Lasserre and Guérineau for the first time at Olympic, and enchanted by their playing, he invited saxophonist to work together. Soon they met again at Foussat's home studio for a first rehearsal. The duo's name, Aliquid, refers to 1957 book Le Je-ne-sais quoi et le presque-rien by Vladimir Jankelevitch.

Aliquid started performing extensively, often accompanied by guest musicians, and recorded two CDr albums in 2005, Le Ton Monte and Mine De Rien. In 2009, the group recorded their 'official' debut album, Aliquid, released by Olympic Café. A follow-up Kriegspiel LP was released through an Egyptian label Olympic Café in 2013.

Soon after Aliquid began playing, Foussat and Guérineau decided to create an expanded version of the ensemble, named Quod (after another Jankelevitch's concept from the same book). First they invited Cathy Heyden, and soon joined by Jean-Luc Cappozzo, the quartet gave their first concert at Olympic Café in September 2006. Since then, Quod has been appearing as a quartet or trio with an ever-changing cast of musicians. One of the sessions by Foussat, Guérineau and Joe McPhee on soprano saxophone was recorded in 2010 at Jean-Marc's home studio, and released four years later as Quod CD album.

Aliquid
Jean-Marc Foussat: EMS VCS 3 synthesizer, electronics, voice
Sylvain Guérineau: tenor saxophone

Quod
Jean-Marc Foussat: EMS VCS 3 synthesizer, electroacoustic instrument, voice
Sylvain Guérineau : tenor saxophone

Cathy Heyden: alto saxophone, voice, toys
Jean-Luc Cappozzo: trumpet, horn

As well as:

Luc Bouquet: drums
Makoto Sato: drums
[a=Jeff Sicard]: reeds
Joe McPhee: reeds, pocket trumpet
eddie135: electronics
Jean-Luc Petit: baritone saxophone
Jérôme Bourdellon: flutes
Francis Larvor: computer
Alex Grillo: vibraphone
Nicolas Souchal: trumpet
Jean-Brice Godet: clarinets, flutes & Dictaphone
Fred Marty: double bass