| 541. Robert "Sput" Searight | Background Vocals, Drums, Percussion | 1 |
| 541. Robert Ackroyd | Guitar | 1 |
| 541. Robert Burger | Guitar, Keys | 1 |
| 541. Robert Cray | Featured Artist | 1 |
| 541. Robert Dillon | Musician | 1 |
| 541. Robert Ellis | Featured Artist | 1 |
| 541. Robert Glasper Experiment | Featured Artist | 1 |
| 541. Robert Gray (aka Robert Gotobed) | Drums | 1 |
| 541. Robert Hurst | Bass | 1 |
| 541. Robert Johnson | Drums | 1 |
| 541. Robert Kearns | Bass | 1 |
| 541. Robert Plant and Alison Krauss | Featured Artist | 1 |
| 541. Robert Stillman | Saxophone | 1 |
| 541. Robert Taylor | Drums | 1 |
| 541. Roberta Leono | Tambor Alegre | 1 |
| 541. Roberto Fonseca | Piano | 1 |
| 541. Roberto Lange | Guitar, Vocals | 1 |
| 541. Roberto Lorenzo | Trombone | 1 |
| 541. Roberto Verástegui | Arrangements, Keys, Piano | 1 |
| 541. Roberto Vizcaino Jr. | Percussion | 1 |
| 541. Roberts | Violin | 1 |
| 541. Robin Baytas | Drums | 1 |
| 541. Robin Bramlett | Bass | 1 |
| 541. Robin Dann | Vocals | 1 |
| 541. Robin MacMillan | Drums | 1 |