Business is related to Downtown. you are likely to find Theater in/at/on Downtown. Theater is related to Musician. 
Rim is a synonym of Border. Border is a synonym of Boundary. Frontier is a type of Boundary. 
Business <--RelatedTo--> Downtown <--AtLocation-- Theater <--RelatedTo--> Musician 
Rim <--Synonym--> Border <--Synonym--> Boundary <--IsA-- Frontier 