Now, if you want another example of an issue which largely postdates the first two centuries of the church, but which has emerged as a major problem in the past century:
While I am most aggrieved by those Restorationist denominations like the Quakers and the Salvation Army which fail to engage in either the celebration of the sacred mysteries of Baptism and Holy Communion even in the very limited way we see among other Restorationist denominations and Protestant denominations of the Radical Reformation (such as Plymouth Brethen, Anabaptists, Mennonites, the Stone / Campbell Movement, the Zwinglians (the Reformed Church in Zurich), the Fundementalist Calvinists and Particular Baptists, and those Evangelical, Fundementalist and Pentecostal churches, it is extremely frustrating how so many churches of these denominations have now moved to reject the traditional hymns and liturgical music of their own denomination and of the rest of the Christian religion (the traditional hymns by Martin Luther, Charles Wesley, etc, consist of simple songs in four part harmony called chorales, some of which were composed recently, by the likes of Sir Arthur Sullivan and Robet Vaughan Williams, but which in many cases, such as “The Old Hundredth” originally used to sing Psalm 100 in French in John Calvin’s church in Geneva, and in English chiefly associated with the hymns “All People On Earth Do Dwell” and the Doxology (“Praise God from whom all blessings flow!”), date from the late 15th and early 16th centuries.
And Gregorian Chant, Mozarabic Chant, Gallican Chant and Ambrosian Chant used in traditional Protestant and Roman Catholic churches, and also in Western Rite Orthodox churches, and their Eastern counterparts such as Byzantine Chant, Znamenny Chant and Georgian Three Part Harmony used in Eastern Orthodoxy, Tasbeha used in Coptic Orthodoxy, the hymns of the Beth Gazo used by the Syriac Orthodox, and the East Syriac chant of the Assyrian Church of the East, are over a thousand years old. Most of this music is closely related, consisting of eight modes or tones (the eight tone system was combined with Renaissance Polyphony and Tonality to produce the esteemed Baroque music of Dieterich Buxtehude, Johann Sebastian Bach and his sons, and other Anglican, Lutheran and Catholic composers, and in the Orthodox East, the exquisite Church Slavonic chant that emerged in Ukraine and Russia in the 18th century, and in the congregational singing known as Prostopinije of the Carpatho-Rusyn Christian minority ethnic group in Eastern Europe, and the related hymnody of the equally persecuted Unitas Fratrum, the Czech Protestants also known as Moravians and as Hussites, who represent the oldest doctrinally orthodox Protestant church in existence, and whose founders, St. Jan Hus and St. Jerome of Prague, are, uniquely among Protestant Reformers, venerated as martyrs by the Eastern Orthodox (specifically by the Orthodox Church of Czechia and Slovakia).
Separately, the music of the Ethiopian Orthodox Church also dates to the First Millenium, and was originally developed by the Ethiopian Jews, who continue to use it, however, the majority of Ethiopians converted from Judaism to Christianity in the fourth century, and unfortunately after the martyrdom of Emperor Haile Selassie in 1974 by the Derg Communist regime, an anti-Semitic policy like that adopted by Stalin in the 1940s and by many other Communist despots was put into place, which resulted in the majority of the Ethiopian Jews, who call themselves the Beta Israel (meaning “House of Israel”), and who, like the Christians, are descended from King Solomon and the Kandake, or Queen, of Sheba, as the country was then known, were forced to flee to Israel, where sadly some of the Rabinnical Jews have treated them in a discriminatory manner (likewise the Karaite Jews, who fled to Israel from Egypt and Syria, and who reject the Talmud and the institute of the Chief Rabbinate, have experienced discrimination; neither group can operate a “Kosher Deli” for example according to their own interpretation of the rules on Kosher, rather, only those delicatessens which follow the interpretation of Jewish law held by the Chief Rabbinate are allowed to call their businesses Kosher, but I digress. Only a few thousand Jews remain in Ethiopia, although I hope that, since the Derg is long gone, more will return, but there is a problem of Islamic terrorism in the country, conducted not so much by the ancient Muslim minority in places like Harar but by Somali and Shifta terrorists who infiltrate the country from the border with Kenya (although most terror attacks against Ethiopian Christians have occurred abroad, for example, about a decade ago, 60 Ethiopian Orthodox were martyred by ISIS in Chad, shortly after the aforementioned martyrdom of 18 Coptic Orthodox Christians and a Ghanaian who declared his faith and was baptized in his own blood, receiving a crown of martyrdom, in Libya.
At any rate, the Ethiopian Orthodox music is particularly interesting, in that it has the oldest system of musical notation in continual use in any country in the world, and is of extreme elegance and sophistication. Ethiopian Christians, along with the Coptic Orthodox and Russian Old Rite Orthodox (many of whom, after Tsar Peter attempted to suppress the Old Rite, much like what Pope Francis is doing, were forced to emigrate to Turkey, Romania, and elsewhere, with many winding up in the US, in Pennsylvania and in Oregon), have the longest church services of any Christians, but of these, the Ethiopian services are definitely the longest, with 24 hour services being held in many churches during Lent and on major feast days (there are breaks where people eat a communal meal, and even at some feasts are given a small ration of beer, which is the only time the more devout Ethiopians will consume alcohol).
Obviously, we are not required to use this traditional music, and there are some good contemporary composers of church music, such as the Estonian Orthodox composer Avro Part, the British Eastern Orthodox convert John Taverner, the Ukrainian Catholic composer Roman Hurko, and the Anglican composer John Rutter, to name four that are well known, three of whom I listen to with some regularity, of whom Hurko and Rutter compose in traditional Church Slavonic and Anglican styles, and Avro Part and John Taverner on the other hand are much more experimental (I have not yet been able to get into John Taverner’s music, but I love the music of Avro Part). But what we are required to do is worship decently and in order, according to St. Paul, and I believe that is impossible when we use Christian Contemporary Music, Praise and Worship Music, “Christian Rock Music” (which I regard as being something of an oxymoron), whereas the ancient liturgical music, the Protestant hymns and the traditional classical worship music I have mentioned does facilitate that.
And among the Restorationist denominations I mentioned at the start, the traditional brass band music of the Salvation Army is lovely, as is the A Capella singing of the portion of the Stone/Campbell movement known as the Churches of Christ, and the beautiful traditional Protestant hymns and organ music used by the Christian Church/Disciples of Christ. Likewise, Baptists historically used a number of traditional forms of hymn singing as well as A Capella exclusive psalmody, which is still the norm among the Reformed Presbyterian Churches in Scotland, North America, and elsewhere, also known as “Covenanting Presbyterians” (whose denominational symbol is a blue flag with the words “For Christ’s Crown and Covenant” written on it. Indeed, I introduced their Psalters into my congregational parishes in order to facilitate congregational singing of the Psalms, which accomplished two objectives: facilitating a transition to Orthodox music while making sure people continued to hear the traditional Protestant chorales they were accustomed to, and also making the Psalms easy to sing, so we would not fall into the trap of having the choir sing them while everyone else merely listened. It is vastly preferrable to the approach taken by most liturgical Protestant churches and a great many Roman Catholic churches using the banal “Ordinary Form” of the mass rather than the traditional Tridentine liturgy (and related uses such as the Lyonaise, Norbertine, Carmelite, Dominican, Bragan, and others), whereby the pastor reads one line of the Psalm and the congregation reads the next line in unison. That approach might be decent and in order, but it is still deeply flawed, because it fails to emphasize the value of the Psalter as the hymnal of the Bible, and also of the value of the Psalms as prayers, for each Psalm is both a prayer and a hymn.
Indeed, the problem with CCM was so bad at my friend Fr. Steve’s Episcopal parish, which I attended for the last year of his ministry before he reached mandatory retirement age (he was the last conservative, traditional Episcopalian Anglican priest that I am personally aware of to serve in the Episcopal Diocese of Los Angeles), due in part to their organist being an enthusiast of it who would work it into the music of their traditional Choral Eucharist so aggressively that the music at their monthly Contemporary Service was actually more relaxed, that except on those occasions when the organist was forced to behave, such as on Christmas Eve, I followed the example of CS Lewis and attended the early morning “Said Service”, which is the traditional Anglican worship service read clearly but without music. In Orthodoxy, except in Western Rite Orthodoxy, we do not have Said Services or the pre-Vatican II equivalent in the Roman Catholic Church, the Low Mass (which was replaced in 1969 with what is basically a Said Service; in a low mass the priest said all of the prayers silently, so all the congregation heard was the appointed Scripture readings and the sacring bell that Roman Catholics ring when they consecrate the Eucharist, except in France where beautiful organ music was played while the priest said the mass; these are sometimes known elsewhere as Organ Masses.