My understanding of the "history" of the shaliach tzibbur (shat"z) is that few people could read or pronounce Hebrew, and, there were few siddurim printed. Thus, the use of an "expert" to represent the congregation in prayers. I gather that the primary usage of the chazzan was for the amidah as we still have the repetition of the amidah, now, even though we also have an individual, silent one.
I assume that other parts of the prayer service such as Psukei Dezimra / the blessing before and after shema, etc. were all done by the chazzan, originally, and aloud, assuming that few spoke Hebrew (I'm uncertain about the verses of Shema, itself, as I don't think the shat"z can fulfill another's obligation to recite Shema.)
Now, that much of the prayers are recited silently, Since when has the chazzan been used as a means of reciting the end of each Psalm, paragraph? What is the purpose for this? Why can't, say, everyone recite silently Psukei Dezimra or the Shema blessings silently and the chazzan should do aloud only Amidah and Kaddish?
- I have seen in many Hassidic shuls (shtiebles) that the shat"z doesn't go to the amud until Yishtabach, so, in fact, Psukei Dezimra is recited "silently". This isn't a universal method, though. Many shuls havethe shat"z recite the end of each paragraph
- I assume that the reason fro having the shat"z recite the Shema blessings aloud is so that the congregation can answer Amen. Is that the only reason?
Please correct me and / or edit any incorrect assumptions that I've made.