The answer is Jozef.
- Regisseur is a Dutch word for director.
- In the context of music, it can refer to a music director or conductor.
- Raoul is a proper noun, likely referring to the music director’s first name.
- Muzikant is a Dutch word for musician.
- Joe is likely a shortened version of the musician’s real name.
- We need a 5-letter word that could be the musician’s full name.
Since Joe is a shortened version of a name, Jozef (Joseph in English) fits the bill as a full name with 5 letters.