 In the UK, almost all jingles heard on BBC Radio 1 and 2 between the mid-1970s and mid-1990s were made by JAM.In the United States, JAM has produced more custom jingles for KOST in Los Angeles than any other station, although WLS in Chicago is very close.JAM's top-selling package has been "Warp Factor," created for Z100 in 1985.