Sentence:  Jeffrey conceives a fascination with nightclub singer Dorothy Vallens (Isabella Rossellini) who sings Blue Velvet, while her abusive, misogynist sugar-daddy Frank (Dennis Hopper) watches, caressing a <WSD>sample</WSD> of this same material. 
Meaning of the word marked with <WSD> tags:  Gratuitous borrowing of easily recognised phases (or moments) from other music (or movies) in a recording.