He is also responsible for layout and/or artwork for albums by his own bands, as well as Zello, Neon Rose, Zeelion, Axia, RAW, Have Mercy and others.
In December 2006 Janne was part of the one-off Sweden Rock All Star Band which also featured Udo Dirkschneider, Ian Haugland, Ryan Roxie, Oscar Dronjak etc.
In 2007 Stark released the debut by his new solo project Mountain Of Power on Grooveyard Records, dedicated to his influences from the seventies, such as Derringer, Moxy, Stray Dog, Captain Beyond and Budgie, featuring guests like Dan Swanö, Björn Lodin, Thomas Larsson, Anders Johansson, Chris Catena, Jonas Hansson, David Fremberg, Mikael "Nord" Andersson and Mike Andersson.
Late 2011 Janne joined melodic rockers Grand Design, who release the single and video of "Baby It's You" on 17 May 2013, a cover of Canadian band Promises.
[15] Grand Design released the album "Thrill Of The Night" (AOR Heaven Europe/Rubicon Music Japan) and the band played the Melodicrock Fest in Chicago on 3 October.
[17] In 2016 Janne recorded a guest solo for Italian prog band Il Rovescio Della Medaglia on the album Tribal Domestic.
[24] In November the same year, Janne recorded a tribute to Welsh hard rock band Budgie under the project name Bandolier Kings.
Other guests includes for example Kyoji Yamamoto of Bow Wow, Ian Haugland of Europe, John Gallagher of Raven and Bill Steer of Firebird.
[27] This album featured guest spots from musicians such as Rob Lamothe of Riverdogs, Carl Dixon of Coney Hatch, Neil Merryweather and more.
[28] and in 2024 the follow-up IV Evermore saw the light of day on the same label, now seeing Janne handling both guitars and bass, plus mixing and mastering the album.
[31] On November 11 Grooveyard Records released the second Bandolier Kings album "Time To Remember", featuring guest spots from Budgie members Tony Bourge as well a musicians such as Andy La Rocque, Rowan Robertson, Doug Rappoport, John Gallagher etc.
[32] In the same month German label Metalville released the CD and LP "Cosmic Affect" by Merryweather Stark Wackerman, an album recorded already in 2019, but not finished until 2022.