JAM jingles have been continuously heard on WLS Chicago since 1976! In 1978 we did our first big WLS custom package for (then PD) John Gehron. It contained over 60 cuts, so for syndication purposes we divided them into two series. One was called "Class Action". The other was named "Pro/Mod" (for PROfessional MODern, PROmo MODules). Since WABC New York also used "Pro/Mod", we produced two versions of the demo. The "A" version featured the WABC cuts, and the "B" version contained the original WLS jingles.