The first four bars were familiar. The fifth made the judge sit up. Plagiarism was a serious accusation. (plagiarism: literary theft, uncredited copying, unattributed copying) A similar tune need not be derivative, and a shared phrase might have a common antecedent. (derivative: unoriginal, imitative, secondhand; antecedent: predecessor, precursor, forerunner) She asked the contestant for the genesis of his song. (genesis: origin, beginning, inception) He said he had learned it while hanging sheets in his grandmother's yard.
Her fellow judge was cynical. (cynical: distrustful, suspicious, skeptical) One could appropriate a melody, offer an uncheckable family anecdote and be home in time for tea. (appropriate: commandeer, take over, seize) The audience was more credulous. (credulous: gullible, naive, unsuspecting) It almost hissed when the first judge asked for the old woman's name. The judge waited until the boy supplied it. Her mother and his grandmother had worked beside the same laundry yard.
She went home to fetch a reel of tape. On it two laughing women kept forgetting the words and inventing new ones. The boy had added a third verse of his own. That was the part they chose to judge. The old verses brought the loudest applause, but the third had earned it a place to start.