Q. Is it right for a chazan to be paid for conducting services on Shabbat?
A. Work is not allowed on Shabbat and one must not allow a servant to do Shabbat work. The issue is whether a chazan is a servant, even if he gets a salary, and whether conducting a service is regarded as work.
The two questions are intertwined. From the technical point of view, leading the prayers cannot be deemed to be work. Otherwise none of us would be permitted to daven on Shabbat, and that would be ridiculous. What about receiving a wage for officiating, even if no forbidden work is involved?
There is actually a rule against paying someone to carry out a non-forbidden act on Shabbat, e.g. acting as a watchman. The Talmud (Pes. 50b) did not debate the issue of paying a chazan since the modern concept of chazanut had not yet arisen, but there is a suggestion that paying someone to translate the Torah reading will bring no blessing because it looks like wages for the Sabbath.
The Shulchan Aruch considers whether this extends to a chazan and says that a chazan should not be explicitly employed for leading the services on Shabbat “but some authorities allow it” (Orach Chayyim 306:5). Rabbi Moshe Isserles adds that if the chazan is hired by the year or the month it is permitted as the weekdays are included and there are duties which his appointment requires of him throughout the year or month.