| Clue | Source | Date |
|---|---|---|
| Notes that altos may struggle to hit | ||
| Soprano's feats | New York Times | 13 Aug 2023 |
| Notes reachable by sopranos | New York Times | 16 Jun 2020 |
| Hard-to-hit pitches? | Wall Street Journal | 03 Aug 2019 |
| Hard-to-hit pitches? | ||
| Hard-to-hit pitches | New York Times | 22 Mar 2018 |
| Hard-to-hit pitches | ||
| Hard-to-hit notes, for some |