Question: What should a person who davens nusach ashkenaz do during kedushah in a shul that davens nusach sefard? Should he use his own nusach or that of the shul he’s in?
Response: This issue is a matter of debate between HaRav Ovadya Yosef, shlita, and HaRav Moshe Feinstein, zt”l.
HaRav Ovadya Yosef (Yabia Omer, VI, siman 10:4) contends that during the silent recitation of kedushah, a person whose minhag is nusach sefard may recite the kedushah according to his minhag even though he may be davening in a synagogue that is nusach ashkenaz. His logic is that since he is not the shliach tzibbur and is davening silently, there is no halachic mandate to alter his personal nusach. (See Maishiv Davar [Netziv], siman 17, who rules that in silent tefillot it is prohibited to deviate from the nusach of one’s family.)
HaRav Moshe Feinstein, zt”l (Igrot Moshe, Orach Chayyim II, siman 23), disagrees. His position is that the obligation to say kedushah is generated by the tzibbur for there is no obligation to recite kedushah when davening alone. Accordingly, even a silent recitation must be in accordance with the nusach of the tzibbur that enabled kedushah to be said. The silent shmoneh esrei, however, may be recited according to one’s own nusach since the obligation to say shmoneh esrei is not dependent on the tzibbur.
Both Rav Yosef and Rav Feinstein agree that any public recitation of a shliach tzibbur should follow the nusach of the tzibbur.
What confuses the matter is that in Israel a number of minyanim don’t follow any set nusach. Rather they follow the nusach of whoever happens to be the shliach tzibbur that day. The Mizrachi Kehilla in Melbourne, Australia once had such a custom. This, however, generated numerous problems. The community thus took a vote to select a nusach (nusach ashkenaz was chosen) and all shlichei tzibbur were mandated to use it henceforth.
I’m sorry to say that here in the USA this preference for a dual standard still exists. One of our members in Florida, a rav, served as shliach tzibbur and davened nusach Sefard in our shul which is nusach ashkenaz. When requested to daven using nusach ashkenaz, he replied that he was given a psak that he had the right to daven in any nusach he desired. My response was that in other synagogues he may so practice, but in our synagogue he had to use nusach ashkenaz in order to be the shliach tzibbur. He capitulated. At no time was I told the name of the posek who gave him this advice.