Answer: Accent
Explanation: Expression is necessary in every artistic performance. Lacking emotional expressions and other factors such as tone, inflection etc. might equate to a bad performance even if delivery was perfect.
Several vocal techniques exist that can be used to assist with
conveying and even enhancing the message within the lyrics. Several of these techniques overlap but there can be subtle differences between them.
The accent is one of such techniques. It is used to add meaning to lyrics, emphasizing a particular word or syllable. The technique can be used to produce unique vocal effects for stylistic differences and versatility.
Accents gives a particular note, syllable, word, or phrase more stress than the ones before or after. Just as italics do it in print, it is exactly the same way accents do it in singing.