What is the ruling on working for a company that builds a music school and an exhibition hall, and what is the ruling if there is no other option?

Music is forbidden, except for the daff (tambourine). Building a school to teach music is therefore forbidden because it is assisting in sin and transgression. Allah Almighty says: (And cooperate in righteousness and piety, but do not cooperate in sin and aggression). Building places where amusement is learned is more forbidden than building places of amusement themselves. Sustenance is abundant for whoever fears Allah. Do not hasten to acquire sustenance by committing what is forbidden, for what is with Allah can only be attained through obedience to Him.