National from a non-community country residing in Europe (example: a malian resident in Belgium)

The principal is that nationals from countries outside the European Economic Area are required to have a work permit issued by the French authorities.
Therefore the French employer of this Malian musician residing in Belgium must apply for a work permit.
The artist is only exempted if he is seconded by a company based in the European Economic Area, provided he is a regular salaried employee of the company (i.e. has been for at least once a year).

Nb >The European Court of Justice considers that salaried persons not nationals of an European Economic Area member state who regularly reside and are on the job market of a Member state that has issued them with the necessary residence and work permits, and who are seconded to provide services by a company established in the European Economic Area, cannot be required to have a work permit by another Member state on the territory where the service is provided. This exemption from a work permit is only possible however if the salaried employees can prove they have already been employed in the company providing the services.

Regarding social security agreements, since 1 June 2003, the provisions coordinating community regulations (nos. 1408/71 and 574/72) also apply to nationals of non-community states who regularly reside on the territory of a European Union member state (except for Denmark).

Nb >This principle results from the Council’s EC regulation 859/2003 dated 14 May 2003 which “applies in all European Union member states (EU) except Denmark, namely the following 14 Member states: Germany, Austria, Belgium, Spain, Finland, France, Greece, Ireland, Italy, Luxembourg, The Netherlands, Portugal, the United Kingdom and Sweden” (…) On the other hand, “the regulation does not apply:

• to Member states of the European Economic Area (EEA) that are not in the European Union (EU), namely: Iceland, Norway and Liechtenstein;
• to Switzerland”.

This musician of Malian nationality residing in Belgium thus benefits from the same social security, private pension (etc.) entitlements as a Community national (See Foreign artist hired by a company based in France, Artist from the European Economic Area ).

As for tax matters, you should refer to the tax agreements; each tax agreement defines residence or domicile for tax purposes.
In your case, you should refer firstly to the Franco-Belgian agreement: if the artist is considered as resident in Belgium for tax purposes, given this definition, the provisions of this agreement apply.

For the Franco-Belgian agreement, “private individuals are deemed resident of the contracting state in which they have a permanent home:

• a. if they have a permanent home in both contracting states, they are deemed resident of contracting state with which they have the closest personal and economic links, namely the contracting state in which they have their main centres of interest;
• b. if the contracting state in which the person has their main centre of interests cannot be determined, they are deemed resident of the contracting state in which they ordinarily reside;
• c. if the said person regularly resides in both or neither of the contracting states, they are deemed resident of the contracting state of which they have the nationality;
• d. s if the said person has the nationality of both or neither of the contracting states, the relevant authorities of the said contracting states shall settle the matter my mutual consent”.

Therefore if this Malian musician has a permanent home in Belgium, the Franco-Belgian agreement applies.