Vandenberghe remained in the Vermeersch orbit, however, among several former XLS members tapped by the reedman to join his new experimental big band, Flat Earth Society (aka FES), formed in 1998. Vandenberghe was present on FES' debut EP, Live at the Beursschouwburg 1999, released by the Viakra label, and on the ensemble's subsequent albums issued by Vermeersch's Zonk imprint (e.g., Bonk, 2000; Minoes, 2002; Trap, 2002; The Armstrong Mutations, 2003), Crammed Discs (Psychoscout, 2006; Cheer Me, Perverts!, 2009), and 13 (Igloo, 2013). Vandenberghe can also be heard on the FES compilation Isms, released by Mike Patton's Ipecac label in 2004.
On the rock side of the equation, Vandenberghe collaborated with XLS/FES guitarist (and mixing/mastering wiz) Pierre Vervloesem on a number of Vervloesem albums including 2002's Grosso Modo (by an improvising rock quartet including bassist Guy Segers and drummer Charles Hayward), 2005's Rude, and 2012's Sketches of Pain (by the XLS-like octet Caca). In the mid-2000s, Vandenberghe also performed with Daniel Denis' dark avant-prog ensemble Univers Zero, appearing on the group's Live album, released by Cuneiform in 2006.
As the first decade of the new millennium was drawing to a close, Vandenberghe began exploring more intimate although by no means traditional acoustic jazz settings, playing piano in Too Noisy Fish, a trio featuring FES bandmates drummer Teun Verbruggen and bassist Kristof Roseeuw. Vandenberghe, Verbruggen, and Roseeuw played Belgian club dates in quartets with saxophonists Ben Sluijs (2009) and Ellery Eskelin (2010) before recording and releasing the piano-bass-drums trio set Fast Easy Sick (produced, mixed, and mastered by Vervloesem) in 2011. Vandenberghe composed nearly all the tracks on the disc, revealing his own unique style drawing from stylistic influences across a wide spectrum of jazz, while also demonstrating considerable improvisational skill and touches of skewed humor. Too Noisy Fish recorded their sophomore disc at a Northern California studio in February 2013; titled Fight Eat Sleep, the album was released in September of that year. ~ Dave Lynch, Rovi