| Musician | Appearances |
|---|---|
| Steven Wilson | 10 albums |
| Richard Barbieri | 9 albums |
| Colin Edwin | 8 albums |
| Gavin Harrison | 4 albums |
| Chris Maitland | 4 albums |
| Theo Travis | 2 albums |
| John Wesley | 2 albums |
| Mikael Ã…kerfeldt | 1 album |
| Adrian Belew | 1 album |
| Lisa Betteridge | 1 album |
| Emmeline Brewer | 1 album |
| Robert Fripp | 1 album |
| Aviv Geffen | 1 album |
| Stuart Gordon | 1 album |
| Sarah Heines | 1 album |
| Eli Hibit | 1 album |
| Katy Latham | 1 album |
| Alex Lifeson | 1 album |
| John Marshall | 1 album |
| Master Timothy Masters | 1 album |
| Nick Parry | 1 album |
| Solomon St. Jermain | 1 album |