In 1971, WLS began calling itself "The Rock of Chicago" in conjunction with the PAMS Solid Rock jingle package. Almost a decade later, WLS revived the phrase in this JAM package, The Rock. The 5-voice vocal group and harder edge tracks were designed to compliment the fuller, 7-voice jingles in the Outstanding package which were also in use at the time. Today, this package stands up well to the rock sounds of 80s music heard on classic hits stations.