On this month in 1972, "Alone Again (Naturally)" by Gilbert O'Sullivan was in its 2nd week as the #1 song for that year, but it became the #2 song overall on the Billboard Hot 100. For the next 4 weeks in July-August and another 2 weeks in September, this song stayed #1 totalling 6 weeks.
On this month in 1965, "I Got You Babe" by husband and wife duo Sonny & Cher became the #1 song for that year and it's also the #16 song overall on the Hot 100 chart. Their #1 hit song would be the closing song on the Sonny & Cher Comedy Hour from 1971-74 on CBS. It stayed #1 for the next 3 weeks.
On this month in 1984, "Ghostbusters", the self-titled movie soundtrack of the same name by Ray Parker Jr. became the #1 song that year and the #9 overall song on the Hot 100 chart. The movie itself became the highest-grossing box office hit with a total of $296.3M and the song stayed #1 for the next 3 weeks.