Providing a singing critique involves telling how well the singer performed, while keeping in mind that the voice is an instrument that can't be separated from the body. Because of this, a singing critique should avoid personal comments about the singer. This makes any negative comments you provide potentially more jarring because a vocalist may take the critique as a personal attack. Stay focused on specific issues common to vocal performance to avoid creating a tense situation while providing the singer with the information needed to improve.
Talk with the singer about her intonation. You should be able to detect whether her singing is flat or sharp. A sharp intonation will sound slightly higher than the pitch, for instance, if you sing the note C and it is sharp, then it will sound somewhere in the middle between C and D-flat. A flat pitch will be slightly lower than the desired pitch, for example, if you sing a C, a flat pitch will sound between C and C-flat.
Discuss the rhythmic accuracy of the performance. Tell the singer whether he was able to sing the rhythms in the piece correctly, or whether he performed with errors in rhythm that need to be corrected. Even without the music, you can tell by listening to whether a solid rhythm is felt when the singer performs. You know when you are singing the rhythm correctly because all of the notes are spaced the appropriate distance from each other in time. For instance, quarter notes are worth one beat each, so four quarter notes would sound equally spaced from each other in time.
Provide an analysis of the clarity of the singer's words. This is called diction, and is an important aspect of singing. If the singer does not articulate words clearly, you must discuss this with her so she can improve her voice.
Evaluate the singer's ability to emphasize the beginning and ending of phrases. A competent singer should know how to end a phrase by breathing in the correct part of the phrase. Avoid breathing during an increase of volume or right before the highest note of the piece. Tell him to breath at the beginning and end of a phrase. If he breathes a beat before the end of the phrase, he must change his breathing pattern to improve. If he has trouble singing a complete phrase without taking a breath, tell him to practice breathing in for four counts and out for eight to improve his lung capacity. Tell him to breathe in through his stomach, rather than his chest.