Slavery is a type of Practice. Perform requires Practice. one thing you do when you Perform is Music. Music can Heal. 
Realm is related to Land. Land is the opposite of Air. Air is a type of Band. Cure is a type of Band. 
Slavery --IsA--> Practice <--HasPrerequisite-- Perform --HasSubevent--> Music --CapableOf--> Heal 
Realm <--RelatedTo--> Land <--Antonym--> Air --IsA--> Band <--IsA-- Cure 