Song: "Must Have Been Crazy"
Artist: Chicago
Peak position on the Cashbox Singles chart: #84
Number of weeks on the Cashbox Singles chart: 4
Weekly data:
| Week ending | Rank | Title | Artist | Label |
|---|---|---|---|---|
| August 25, 1979 | 88 | Must Have Been Crazy | Chicago | Columbia 11061 |
| September 1, 1979 | 85 | Must Have Been Crazy | Chicago | Columbia 11061 |
| September 8, 1979 | 84 | Must Have Been Crazy | Chicago | Columbia 11061 |
| September 15, 1979 | 89 | Must Have Been Crazy | Chicago | Columbia 11061 |
Rankings greater than 100 are from the Cashbox 'Looking Ahead' charts.