Assuming the story takes place in present day and that Johnny kept up his payment plan ($12.50/month for 400 months), he would have finished repaying the $5000.00 in late May 2012.
The songs in the contest in order are: "Too Wild to Tame" by The Boyz, "Tumbling Dice" by The Rolling Stones, "YMCA" by The Village People, "Dankeschoene" by Wayne Newton, "Straight On" by Heart and "The Star Spangled Banner" by Francis Scott Key.
A bright red album with "Bad Boy" on the cover can be seen throughout. Bad Boy is a Milwaukee, WI based rock band who were on the verge of stardom back in the '70s and '80s. The album featured is titled Back to Back.
Because music licensing deals had expiration dates, WKRP often changed the music to generic music or re-recorded songs with studio musicians for reruns or DVD releases. This is very clear, as the songs in the contest as shown in streaming video are different and much less known. Since the characters naming them are unseen, it is easy to do a voice-over with a sound-alike actor. In the rebroadcast, the songs are: "Rolling" by No Big Fish, "Give in to Love" by Cinema 8, "Take Me Home" by Raquel Wood, "Leave" by Suzie, "The Life of the Party" by Eric Scott, and The National Anthem by Francis Scott Key (uncovered by copyright).
"Don Pesola," the caller who gets the impossible six songs on the first try, is the real name of longtime Buffalo WKBW disk jockey (and later WBEN voice) "Sandy Beach." Buffalonian and KB alum Casey Piotrowski is the co-writer, supposedly basing the story on an actual event at KB (as was the turkey drop, which hit the ground at Cheektowaga's Thruway Plaza).