Berakhot 084

1:
At first glance it would seem that there is no connection between this mishnah and its predecessor or its successor; indeed, it seems to be an interloper disrupting the continuity between them. However, it seems to me that the purpose of the editor of the Mishnah in placing this mishnah at this point in the chapter is to indicate that although we are dealing principally with the Amidah, which is a required prayer whose parameters have been fixed, this does not preclude private and personal prayer in addition.

2:
The Talmud of Eretz-Israel [Berakhot 7d] gives the text of the prayers attributed to Rabbi Neĥunyah ben-Hakkanah:

Rebecca Grabiner writes:

I have a question about the manner in which the Kedushah is recited. I have sometimes seen the cantor begin the Kedushah, singing alone until the first place where the book says "Congregation." Then everyone except him sings "Kadosh, kadosh, kadosh [etc.]" but does not stop at the end of the line, instead continuing as fast as possible through the section (marked "Reader" in almost every prayer book I have used), finishing at "Baruch yomeru," right before the next place which is marked "Congregation. Then the cantor repeats alone from "Kadosh, kadosh, kadosh" through "Baruch yomeru," and the rest of the Kedushah goes on in the same fashion. I am not certain if this is part of "Heuche Kedushah" or not because I seem to recall seeing it both in cases where the Amidah was first recited silently and in cases when it was not (I could, however, be wrong about this because I have not seen it done for a while). Is this reading aloud with repetition supposed supposed to serve the same function as the silent reading followed by the cantor's repetition? If this is the case, why is it only done in the Kedushah (I have never heard the Avot or the Gevurot recited this way)?

I respond:

What Rebecca has described is a very widespread way of reciting the Kedushah in Ashkenazi congregations. First of all this term, Kedushah, must not be confused with the term "Heuche Kedushah", which was described in Berakhot 080. You will recall that the term Kedushah or Kedushat ha-Shem is the name of the third berakhah of the Amidah. When the Amidah is recited silently this berakhah is quite short: "You are holy, Your Name is holy, and the holy beings praise You daily. Blessed are You, Adonai, the holy Deity". The "holy beings" referred to obliquely in this text are angels, and the germ of the idea comes from the vision of the prophet Isaiah described in chapter six of his book. A school of mystics, whose origins are to be located some time in the period of the Second Temple and whose influence continued well into Talmudic times and beyond, was called Yordei Merkavah. They developed an extensive angelology (later to be inherited and further developed by Kabbalah). This school of mystics developed Isaiah's vision into a regular heavenly chorus whose constant pleasure it is to laud the Deity, using the quotes from Isaiah and Ezekiel mentioned by Rebecca. Thus an enlarged version of the third berakhah of the Amidah came into existence, that outlines the activity of this mystical heavenly chorus. In Eretz-Israel this enlarged version was used only on Shabbat and Yom-Tov; in Babylon it was used every day. Today, when people popularly refer to "the Kedushah" it is to this that they are referring.

Strictly speaking, the manner of reciting this Kedushah as described by Rebecca is mistaken. Since it is an integral part of the Cantor's repetition of the Amidah, the Cantor should recite every single word of the Kedushah out loud, and the congregation should not interrupt except to join in with the Biblical quotations – and indeed this is how it is done in Sefardi congregations. However, I doubt that the ingrained mistaken custom that Rebecca describes could now be eradicated.