[2] At the Splash Festival 2009, rapper Bernd Bass (Felix Brummer) performed together with the rock band Neon Blocks for the first time.

[5][6] Kraftklub have performed as the support act for bands including Beatsteaks, Fettes Brot, Casper, Die Toten Hosen, and Rammstein.

[11] On 6 April 2012, K.I.Z and Kraftklub gave an unannounced concert on the roof of the Chemnitz commercial complex Terminal 3 as part of the documentary film series Durch die Nacht mit ... commissioned by Arte.

The performance was announced only a few hours before via social networks, despite the ban on dancing on Good Friday, and as a result of the crowds of spectators the police closed off the Chemnitzer Brückenstraße.

and Die Ärzte also withdrew their participation, Frei.Wild was removed from the list of nominees and Kraftklub received the "Kritikerpreis National".

Kraftklub has a guest appearance in the song "Ganz schön okay" on the album Hinterland by German rapper Casper.

The band started their KARGO tour in November 2022 at a number of dates in Germany, one in Vienna, Austria, and one in Zurich, Switzerland.

Starting with the release of his first single 9010 on June 11, 2019, Felix launched his solo rap-career, performing simply under his last name Kummer.

It is noteworthy, that his performing and last name Kummer, at the same time, is a german word meaning sorrow or grief, reflecting in some way the overall sentiment of the album, which also is the motive of the first song of the album "Nicht die Musik" (Not the music [you're looking for]) as well as the theme of the aforementioned non-album single "Der letzte Song (Alles wird gut)".

Concurrently, underlined by his resolute rapping tone, he comes across as confident with having a fighting spirit, which gives most of his tracks also a positive and hopeful undertone, indicated as well in the chorus of, along with its alternative title in brackets itself, "Alles wird gut" (everything will be good).

His last two concerts as Kummer he performed in front of a sold-out audience at the Parkbühne Wuhlheide open-air venue in Berlin.