Crowd is related to Chaos. Chaos is related to Crisis. 
Hire is similar to Rent. Rent is a type of Musical. Musical is related to Drum. Drum is related to Rock. 
Crowd <--RelatedTo--> Chaos <--RelatedTo--> Crisis 
Hire <--SimilarTo--> Rent --IsA--> Musical <--RelatedTo--> Drum <--RelatedTo--> Rock 