Voice
| Daniel Ottevaere | Valenciennes | Since 2007 |
| Mitsuko SHIRAÏ | Stuttgart | 1999, 2002 to 2005; since 2010 |
| Harmut HÖLL | Stuttgart | 1999, 2002 and 2004 |
| Jard VAN NES | The Netherlands | 2001 and 2006 |
| Elizabeth COOPER | Paris | 2001 |
| Ulrich EISENLOHR | Detmold | 2001 |
| Walter BERRY | Vienna | 1996 to 2000 |
| Paul VON SCHILHAWSKY | Salzbourg | 1993 to 1995 |
Violin
| David GRIMAL | Paris | 2011 |
| Philippe GRAFFIN | Paris, Brussels | 2011 |
| Zakhar BRON | Cologne, Zürich, Madrid | Since 2005 |
| Priya MITCHELL | Frankfurt | 2009 |
| Marco RIZZI | Detmold | Since 2001 |
| Ralph EVANS | USA | 2003 |
| Viktor PIKAYZEN | Moscou | 2002 |
| Yuzuko HORIGOME | Brussels | 2000 |
| Edith PEINEMANN |
Frankfurt & Lucerne |
1999 |
| Igor OZIM | Bern | 1998 |
| Igor OISTRAKH | Brussels | 1997 |
| Philip HIRSHHORN | Brussels | 1993 to 1996 |
Viola
| Christoph SCHILLER | Basel | Since 2008 |
| Matthias BUCHHOLZ | Cologne | 2005 to 2008 |
| Michael KUGEL | Gent and Maastricht | 2003 |
| Hugh MACKENZIE | Paris | 1993 |
Cello
| François GUYE | Geneva | Since 1994 |
| Jeroen REULING | Arnhem, Brussels |
Since 1994 |
Piano
| Jean FASSINA | Paris | Since 1993 |
Chamber music
| François GUYE | Geneva | Since 1994 |
| PRAZÁK Quatuor | Praha | 2004 |
Clarinette
| Michel ARRIGNON | Paris | 1994 to 1997 |