I have been looking at the Billboard Charts for July 21, 1979 and noticed that on that week Blondie's Song "One Way or Another" returned to the Top 40 after being off for one week. Does anyone have the AT40 show for July 21, 1979 and if so, could they tell me whether or not Casey said anything about this. From what I see such a one week drop and return to the Top 40 was rare at that time, but I may be mistaken.
I've been wondering the same thing. I do know for a fact that this was the last time such an event would happen for eleven more years. In the late spring, "Always And Forever" by Whistle debuted at 39, then disappeared for a week and came back. Casey referred to the Blondie "encore" as the last time this had happened. The charts were indeed becoming more interesting in 1990. Before that fall, "Get Closer" by Seals & Crofts was the last song to hit the Top Ten, fall out and re-enter. Then, it happened twice within a few months' time. First, "Epic" by Faith No More committed such a feat (this was especially remarkable, as they surpassed their previous peak, moving 13-10-11-9). Then, later that year, "Knockin' Boots" by Candy Man hit the Top Ten twice. (11-9-11-10). Of course, once AT40 began using the Top 40 Radio Monitor, weird chart moves abounded.