One of the essential qualifications for leading the davening in shul is a pleasant, melodious voice. Sefer Chassidim writes that a person blessed with a pleasant voice should use it for davening to Hashem and praising Him, and not for mundane purposes. On Shabbat in particular, the shliach tzibbur (individual leading the services) is expected to daven loudly, beautifully, and at length in order to inspire the congregants and enhance their davening.
Shulchan Aruch states that a shliach tzibbur who davens at length, utilizing his voice to inspire his fellow congregants, should be commended, but one whose intention is simply to show off his vocal abilities is contemptible. It’s related that some gedolei Yisrael (leaders of the Jewish people) would keep this text of Shulchan Aruch in front of them while serving as shliach tzibbur in order to be constantly mindful of their objective: to enhance the davening of those present, not to exhibit their talent.
Rav Yosef Yeshaya Braun, shlita, Mara D’atra and member of the Badatz of Crown Heights, Day-To-Day Halachic Guide, #62, reprinted from crownheightsconnect.com
