Lens is a type of Plant. Plant is related to Forest. Forest is a type of Single. 
Horn can be used for Music. Classical is a type of Music. Classical is a type of Album. Recession is a type of Album. 
Lens --IsA--> Plant <--RelatedTo--> Forest --IsA--> Single 
Horn --UsedFor--> Music <--IsA-- Classical --IsA--> Album <--IsA-- Recession 