It would be good to point out here that we should probably exclude changes like this which were implemented away from the battlefield over reform (or in an earlier period). For example, R. Zvi Hirsch Chajes advocated a more moderate position about customs, namely that while it is true that customs can and do change, the only legitimate way for that to happen is naturally. As an example, he mentions piyutim (liturgical poems). In Western Europe the reciting of piyutim became a major, major flashpoint. Removing or advocating for their removal was almost seen like apostasy. Yet, wrote Chajes, in Eastern Europe they had been quietly fading away without fanfare. Eventually this is what happened in, what I think is safe to say, most of Orthodoxy. (No need to give counter examples; I know loads of shuls say piyutim and say 'em all with gusto.) Another example would be shluggen kaporos with a chicken. While there has been a major, visible revival in recent decades, it also almost became extinct and I assume that happened without fanfare or a struggle. So even though this type of thing should also be documented, I take it as a related phenomenon. What I want to discuss is an example of reforms which took place on or near the battlefield, even if technically late in the battle.
Before I do, it would be good to cite from R. Akiva Yoseph Schlesinger's Lev Ha-ivri (Lemberg 1864) because it is a good example of the strict, Change-Nothing attitude. His book is a 100+ page commentary on the Chasam Sofer's ethical will to his family (which is only a couple of paragraphs long). Commenting on the Chasam Sofer's words that they should not get "close to the modernists who arose to distance us from God and his teaching, due to our sins," Schlesinger gives examples of what it is that the modernists have done in his time. He writes "at the time they only began to assert their new ways on small things, such as to abolish undecorous customs like the following: schul kloppen, haman kloppen, mitzvos ausrupen" (i.e., knocking on windows to wake people to come pray, knocking when Haman's name is read on Purim, announcing the sale of honors in the synagogue [at least that's what I think he means]) "and announcing the day of the omer count, announcing the time for Kabbalat Shabbat an hour before the time, and not announcing the name of a person as he is called to the Torah [instead, a card was given and they would just walk up at the right time]."
In a footnote he gives his view that perhaps the underlying cause of the end to selling aliyos and the like is because it indicates that these are unimportant in the public's eyes and they do not chase after God's commandments, and do not value them. Rather, they are embarrassed of them. In the next footnote he calls attention to the din that the child of a mamzer is not called to the Torah by his father's name, nor the son of an apostate, and the point is not to embarrass him. He sarcastically asks why the reformers didn't use this as a precedent. He then asks, seriously, why didn't the great rabbis of the past abolish calling up by the fathers' name altogether, in times when it was literally dangerous for a convert, yet they required that he be called up by name, Avraham ben Avraham?
The point is that this is the attitude that I was referring to above. Small customs should also not be abolished, and ultimately having a cavalier attitude toward them leads and led to much larger breeches. There's another fascinating footnote here about the Rema and his attitude toward minhagim, even ones which seem bad, but I'll leave that for another time (or, you can read it here).
In 1892 four British congregations under the auspices of the United Synagogue wanted to make some liturgical reforms. Their rabbis ("Ministers") got the Chief Rabbi Hermann Adler's attention, and the approach he took was to carefully review what they had in mind, and to respond what he would and would not permit. This was published as a pamphlet called The Ritual - the Reply of the Chief Rabbi. In the introduction (and the text) he makes it clear over and over again that the whole matter was not something he was happy about. He makes it clear that that which he allows should be regarded as optional by other congregations, and it would definitely be better if they did not adopt these changes but retained everything exactly as it was.
Should any congregation seek to adopt them, he strongly urges them not to "mar the peace and brotherly union" which is supposed to exist in shul, and that great care must be taken not to alienate anyone who is opposed. Nothing should be changed without a majority of members approving it; what's more, these members must be the ones who actually attend the prayers.
He makes it clear that he permitted everything that does not violate the din. In addition, he takes them at their word that their sole intention is to enhance the "impressiveness" of the services, and for this reason he also adds some suggestions of additions they could make which would "stir prayerful sentiments." He writes that these additions are not "innovations."
He ends his introduction with some advice that to really make their prayers meaningful they should make strenuous efforts with their children. Make sure they acquire a sound knowledge of Hebrew. Make sure there is prayer at home. You must be observant at home. Teach your children, and lead by example. Let them see that the daily practice of Judaism enhances life. And if you do this, then they will "preserve the same deep reverence, the same unbounded love, the same true-hearted loyalty to the Synagogue and its services which inspired their fathers of old" i.e., not you.
He then holds his nose (figuratively) and gets down to the business of permitting liturgical reforms. I will only mention the ones I found most interesting as examples (note that the pamphlet is highly organized. Each item - 44 in total - includes a little note as to which synagogue(s) requested that particular change).
1. The first one concerns the minyan (quorum of ten men) itself. He writes that some people believe that without a minyan there should be no prayer service at all, but this is a mistake. This being an issue in some of the smaller congregations out in the boondocks, he says that what they presently do, which is to wait for a minyan, and then leave if none is assembled, is wrong. A shaliach tzibbur should lead, with the same solemnity as with a minyan, only certain things which require a minyan should be omitted, such as kaddish, barechu, and the repetition of the Amidah with kedusha. He even says that the Torah should be taken out and read - only without aliyos. The haftarah should also be read, only without a blessing. If a mourner is present, instead of saying kaddish he should say Anah adonay maleh rachamim. And he closes this section with a reminder to make great efforts to ensure that there is a minyan.
2. The second is one which he does not permit. The suggestion that men would recite "who hast made me according to Thy will" is not allowed by him. He repeats the standard explanation that "hast not made me a woman" refers to relative number of commandments.
3. One of the more interesting ones. Regarding the hazzan's repetition of the Amidah, on shabbat and holidays: "After the gravest consideration of the subject, I have come to the determination that I am justified in following herein the practice of the Sephardim congregations, both here and in Amsterdam, whose rigid adhesion to our traditional enactments has never been impugned. These congregations read the Tefillah at at the Week-day Afternoon Services, and at the Mussaf on Sabbaths and Festivals only once. I therefore concede that the Amidah of Mussaf on Sabbaths be recited in the following manner:
He continues that all other times, including of course the Mussaf of Rosh Hashanah and Yom Kippur, the repetition must be retained.
4. A very interesting item. He writes that the time Shabbos begins was fixed "by the learned Chacham Nieto" (in the 18th century) and there is no reason to make a change, without the concurrence of "the present Chacham" (i.e., Moses Gaster).
5. He allows the omitting of Bameh Madlikin, but recommends it being read prior to Minchah.
6. He allows an early service at 8:00 or 8:30 AM on Shabbat or holidays. (He doesn't say it, but my guess is that at least some of the people who wanted this wanted to get on with their day; likely some wanted to work. However, neither hour seems particularly late, and I can't see how he would have allowed it if he perceived that as the motivation for the request.)
7. Definitely one of the most interesting. He says that they asked that the Decalogue be read in the synagogue on Shabbat. The intention was to impress the minds of young and old. Furthermore, they claimed, they hoped that reading the 4th Commandment would stir some of the congregants to revere the sabbath and prevent them from desecrating it. Adler of course notes that this is forbidden by the Shulchan Aruch OH 1:5 based upon BT Berachot 12. However, based upon the Maharshal #54 he decided to permit it. (This is by far the most explicit halachic discussion he made in the pamphlet. Everything else comes off as if by fiat. I assume he was aware that some would know that the reading of the Ten Commandments is explicitly prohibited.) He says that based on this Maharshal he allows the Decalogue to "form part of the Bible Reading on Sabbaths." He says that it should be read after the Torah reading, and he also suggests that several other Bible passages (he gives five) be alternated with the Decalogue, so as to further prevent the impression that this is the only part of the Torah divinely inspired (as per the heresy which the Talmud meant to guard against).
8. Addressing one shul in particular, he "concede[s] with great reluctance" that they may begin praying at the late hour of 9:45. He hopes that this will induce more people to come on time, and gives the caveat that all three paragraphs of the Shema be read "at the first recital." Also in this section, he approves of regulating each section of the davening by time, with the caveat that this not cause anything to be hurried.
9. The mother of all: "I concede the omission of the first yekum purkan."
10. The Birkhat Kohanim must not be omitted. In those days many people were uncomfortable with the idea of a hereditary priesthood, and, besides, many kohanim did not hold themselves worthy. Adler (himself a kohen) says this is a misperception; it is not the kohen, but God, who blesses the Congregation.
At this juncture I relate a story about how in fact the gradual dissolution of Birkhat Kohanim was common in those times. In the pulpit occupied decades later by Rabbi Louis Jacobs, it would have disappeared as well, were it not for Rabbi Hermann Adler's own half-brother, the bibliophile Elkan Nathan Adler, who prayed there and asserted his right to bless the congregation.
12. Although he allows Adonay adonay to be recited only one time when the Torah is taken out on holidays, he says "there is no valid reason why the ancient usage of chanting the kol nidrei three times should be altered."
12. Although he rejects the proposes substitution for the Torah portion read at Minchah on Yom Kippur, he takes it seriously ("claimed my most serious attention"). He said that the Talmud Megillah 31 is clear and precise and it was indeed relevant and important to "inculcate . . . the great duty of sexual morality" on Yom Kippur. He endorses a suggestion that a little essay be inserted into future editions of the machzor explaining the importance of it.
13. He rejects the idea to not recite Ma'ariv at the conclusion of Yom Kippur. He says that in many synagogues it is read while people are bustling about noisily to leave and go home. He gives a solution for trying to make Ma'ariv more decorous, with more time left for it.
14. He does not allow sounding the Shofar on shabbat.
15. In response to a claim that the monetary obligations in the ketubbah are not fulfilled, and that the text should be revised accordingly, he denies that there is a reason to assume that "in all cases" it is not fulfilled. He also suggestions that changing the wording of the ketubbah might have the effect of "impair[ing] the recognition of the religious validity of the marriage."
16. In one of the appendices (including additional prayers, and lists of piyuttim and selichos that he allows to be omitted) there is one called Questions That May Be Addressed to the Bridal Couple. Here is one he allows:
Mesader Kiddushin: "You A.b. and C. D. are about to be wedded according to the law of Moses and Israel.
"Will you, A.B., take this woman, C.D., to be your wedded wife? Will you be a true and faithful husband unto her? Will you protect and support her? Will you love, honour and cherish her?"
Chosson: "I will."
you may read or download the entire pamphlet here.