Class is related to Level. Level is related to Leave. Leave is a synonym of Forget. Forget is a different concept from Recall. 
Singer is a type of Musician. Singer is related to Artist. Artist can Paint. one thing you do when you Paint is Art. 
Class <--RelatedTo--> Level <--RelatedTo--> Leave <--Synonym--> Forget <--DistinctFrom--> Recall 
Musician <--IsA-- Singer <--RelatedTo--> Artist --CapableOf--> Paint --HasSubevent--> Art 