Who can serve as a cantor?

Dear Rabbi! We have a man in our community who has a wonderful voice. However, unfortunately, he is not Shabbos-observant. The people who are responsible for our synagogue are interested that he lead the prayers on Rosh Hashana. Is there a problem with that?  

Dear …!

The Sages call the cantor “the emissary of the public”, since his goal is not to please the public with pleasant and melodic singing. Rather, his mission is to be his congregation’s emissary to bring their prayers up to Hashem. If the cantor is not an upstanding, moral person, then, not only will his prayers not be willingly accepted, what will happen is quite the opposite, G-d forbid. The Talmud states that the prophet (Yermiyahu 12:8) said about this: “she raised up her voice against me, therefore, I hated her”. Because of this, halachic authorities write that on the Days of Judgement one should be extremely careful to appoint a cantor who is G-d-fearing and known for his righteous deeds. Such a person will be able to bring everyone’s prayers up to be accepted willingly by Hashem.

May all your prayers be readily accepted.   

Tractate Taanis 16b; Shulchan Oruch, section Orach Chaim, chapter 581, §1