| Year | 2007 |
| Date | 16-Feb |
| Volume | 198 |
| Issue | 4,293 |
| Page | 213 |
| Category | General |
| Part | 98 |
| Title | Letters to a Grandson |
| Author | M.J.H. Ellis |
| Notes | Explains more of the mysteries of sound frequencies. A happy fact, logical basis, intervals between notes of diatonic scale, lower and upper tetrachords |