Verification of truth – "In every singing, it should have ____." Identify the necessary element.

Introduction / Context:
In exam usage, “singing” typically implies vocalization of lyrics; chorus/drum/musician are optional adornments.

Given Data / Assumptions:
Scat/humming exist, but the intended conventional answer is “words.”

Concept / Approach:
Pick the element most intrinsic to typical singing.

Final Answer:
Words