Song: "In Your Letter"
Artist: REO Speedwagon
Peak position on the Cashbox Singles chart: #28
Number of weeks on the Cashbox Singles chart: 13
Weekly data:
| Week ending | Rank | Title | Artist | Label |
|---|---|---|---|---|
| August 8, 1981 | 82 | In Your Letter | REO Speedwagon | Epic 02457 |
| August 15, 1981 | 66 | In Your Letter | REO Speedwagon | Epic 02457 |
| August 22, 1981 | 50 | In Your Letter | REO Speedwagon | Epic 02457 |
| August 29, 1981 | 43 | In Your Letter | REO Speedwagon | Epic 02457 |
| September 5, 1981 | 36 | In Your Letter | REO Speedwagon | Epic 02457 |
| September 12, 1981 | 33 | In Your Letter | REO Speedwagon | Epic 02457 |
| September 19, 1981 | 30 | In Your Letter | REO Speedwagon | Epic 02457 |
| September 26, 1981 | 28 | In Your Letter | REO Speedwagon | Epic 02457 |
| October 3, 1981 | 28 | In Your Letter | REO Speedwagon | Epic 02457 |
| October 10, 1981 | 38 | In Your Letter | REO Speedwagon | Epic 02457 |
| October 17, 1981 | 48 | In Your Letter | REO Speedwagon | Epic 02457 |
| October 24, 1981 | 59 | In Your Letter | REO Speedwagon | Epic 02457 |
| October 31, 1981 | 96 | In Your Letter | REO Speedwagon | Epic 02457 |
Rankings greater than 100 are from the Cashbox 'Looking Ahead' charts.