In 2004, under the alias John Rock, he began in 2004 in a successful collaboration with house duo Musikk with a number of No.

That same year he released his second solo studio album Today is a Good Day (To Fall in Love).

He released his solo Danish language single in May 2007, entitled "Lidt endnu" (meaning Just yet) In August 2007 landed a job as a radio host on commercial station Radio ABC in the program Mads og Jon[1] In 2009, his management company IDOLINC released Remady P&R's "No Superstar" throughout Scandinavia.

In June 2011 he released "Fester Kun Med Mig Selv" reaching number 39 on the Danish Singles Chart.

16 April 2007 saw the premiere of the documentary Solo, directed by Kasper Torsting dealing with Jon's story after winning Popstars.