If one has not completed his Shemoneh Esrei before the Chazan reaches Kedusha, is it permissible for him to hum along with the Chazan’s nigunim (without reciting any words)?

While it is customary to recite Kedusha every day, the Maseches Sofrim [1] states that it was said only on days when Mussaf was recited. In fact, Tosfos [2] writes that this was the original practice in Eretz Yisrael, but over time the universal custom has become that Kedusha is said every day. However, the Shabbos Kedusha is unique in that it consists of additional sections. It is these extra sections that are often sung on Shabbos and Yom Tov, but are those sections actually part of Kedusha?

The Kedusha section of davening is of a unique quality, and one should be fastidious about answering Kedusha along with the tzibbur. The Mishna Berura [3] writes that one should have in mind to fulfill the mitzvah of ונקדשתי בתוך בני ישראל when reciting Kedusha. In fact, some Poskim write that it can be more important than תפילה בציבור [4]. Therefore, one should do his best to be on time so that he can complete his private tefillah in a timely fashion to then answer Kedusha. If one is amid his personal tefillah when Kedusha begins, the Rishonim debate what he should do. The Beis Yosef [5] cites Rashi and Rabbeinu Chananel who say that one should pause their own davening and listen to Kedusha from the chazzan, while Rabbeinu Tam argues that if one listens and utilizes שומע כעונה it would be tantamount to interrupting his own tefillah and therefore he should continue his personal tefillah without any pause. The Shulchan Aruch [6] sides with Rashi and writes that one should pause and listen while the chazzan recites Kedusha. But the Mishna Berurah [7] is clear that the core of Kedusha are the lines of קדוש וברוך, and regarding ימלוך it is debatable if that too is considered part of the core Kedusha but the additional text added on Shabbos is not part of the Kedusha and therefore one need not hear it from the chazzan. It should then emerge that once the chazzan reaches the melodious section i.e. ממקומך one can actually resume his private tefillah as he need not hear the Chazzan. However, Sefer Ishei Yisrael [8] cites some Poskim who believe that that one should remain silent until the conclusion of the Bracha of אתה קדוש.

Because those still reciting their personal tefillah must hear the main sections of Kedusha from the chazzan, congregational singing should not drown out the chazzan. In fact, R’ Moshe Feinstein [9] notes that the chazzan must say the words aloud, and he should not be drowned out by the tzibbur, so that those who are amid their own silent tefillah can hear him clearly. However, the congregation may sing ממקומך and other added sections because one need not hear from the Chazzan. It would emerge that even one who is still amid his personal tefillah may hum along as well. This is because the singing is connected to the words being said by the chazzan, we wouldn’t view the humming as a הפסק [10].

[1] 20:5

[2] Sanhedrin 37b d.h. M’Knaf

[3] 125:4. See Tashbetz (2:163)

[4] See Ishei Yisrael, 33 footnote 31 and Shulchan Aruch 109:1.

[5] 104:7

[6] ibid

[7] 125:1

[8] 32 footnote 53

[9] Iggros Moshe 3:4

[10] See Magen Avraham 128:73, Shevet Halevi 5:16. Moreover, although long silent breaks during one’s private tefillah may necessitate resuming the tefillah at an earlier point as it is deemed a הפסק (see Shulchan Aruch 104:5), humming while focusing on the words is less of a הפסק and thus less of an issue (see Kaf Hachaim 36).