I am cross-posting this with my other blog, Notes from a Byzantine-Rite Calvinist.
It is not difficult to find Christian theologians and liturgical scholars commenting on what makes for a good hymn text. For example, I recently read J. Gresham Machen's Christianity and Liberalism, in the course of which he discusses the merits of three familiar hymns, Nearer, My God, to Thee, In the Cross of Christ I Glory and When I Survey the Wondrous Cross, the last of which he judges superior to the other two, due to its obvious grasp of the place of the cross in the economy of salvation. Similarly, following the church fathers, the reformers and many others, I myself am persuaded that the psalms must have a pre-eminent place in the church's liturgy. So much for texts.
But what of the church's music? Is there better or worse music by which to worship the Triune God? Are some genres better suited than others to the liturgical assembly? Does it really matter whether we use organs, unaccompanied voices or electric guitars? Isn't it all finally a mere matter of personal taste? That's what many would argue. I strongly disagree. Although one could write an entire treatise on the subject, I will limit myself to putting forth a few principles for consideration.
1. The tune must fit the text. Even if their metres are identical, not every text necessarily goes with every tune. A particularly egregious violation of this principle is found in the 1957 edition of the Christian Reformed Church's Psalter Hymnal. Number 158 is a metrical versification of Psalm 83 set to FOREST GREEN. The text is one of the imprecatory psalms, calling down God's wrath on his enemies, which would seem to require something less obviously cheerful than FOREST GREEN. (Happily, this unfortunate pairing of text and tune did not make it into the 1987 edition.)
2. Avoid pairing texts with a tune too obviously associated in the popular mind with another text or occasion. The Scottish Psalter's The Lord's My Shepherd, I'll Not Want could conceivably be sung to Lowell Mason's ANTIOCH, but given that the latter is a familiar Christmas tune, it is probably not wise to do so. It may also be illegal in some cases. About three decades ago, some churches were singing a liturgical benediction to Richard Rodger's tune for Edelweiss, from The Sound of Music. Rodgers himself and, later, the executors of his estate were definitely not amused.
3. The music should not overwhelm the text but ought to be ancillary to it. There is something to be said for unaccompanied unison singing, as found in, e.g., the Orthodox Churches and 16th-century Geneva. Reformed Presbyterians allow for part-singing but without musical instruments. While most Christians do not see fit to embrace such seemingly austere practices (and for good biblical reasons; see Psalm 150), it is nevertheless true that excessively flashy organ-playing or loud guitars and drums come dangerously close to violating this principle. Instruments should precisely accompany singing, not dominate it.
4. Music for the congregation must be fairly simple in structure, both rhythmically and musically. It certainly should not distract from the text being sung. Here a distinction must be made between those tunes meant for congregational singing, on the one hand, and solo and choral singing, on the other. I leave aside the latter for now, except to note that choirs and soloists generally take on more challenging music than the typical congregation can be expected to.
Several years ago I wrote a metrical version of the Apostles' Creed, which I titled, Credo in Septuple Metre. The tune I came up with, LUSIGNAN, is actually a fairly simple one, but the time signature, 7/8, may make it unsingable by an ordinary congregation, except perhaps by one belonging to the Greek Evangelical Church, where such rhythms would be familiar. It would thus probably make a better solo piece. On the other hand, the moving hymn, Gift of Finest Wheat, is included in many hymnals and is beautifully sung by congregations, despite its alternating 4/4 and 3/4 time signatures. This demonstrates that the musical ability of many congregations should not necessarily be underestimated.
5. While the melody should be simple, it must also be memorable, which is to say, distinctive enough to stick with people. This implies a certain degree of movement in the tune. For example, Lowell Mason's HAMBURG is well-known and easily sung, though in my view it is not an especially strong melody, consisting entirely of a series of ascending and descending partial scales. Ascents and descents invariably move one step at a time, and the entire tune spans only five notes. This gives it the undoubted virtue of not unduly taxing the singer, but leaves it with the corresponding defect of not being very interesting.
By contrast, Edward Miller's ROCKINGHAM, which has the same metrical structure, is a much stronger melody, spanning a whole octave, with the movement reaching two obvious climaxes in lines 2 and 3. The motion of the tune sometimes moves by thirds and fourths, and even drops by a sixth after the second high note. ROCKINGHAM is simply a more dramatic tune and better communicates the story of redemption.
When I was a graduate student at Notre Dame in the early 1980s, I wrote a versification of Psalm 137 and came up with this tune. When I showed it to a professional musician who was a member of my church congregation, he told me there wasn't enough movement in the melody. I took his critique to heart, scrapped that tune and came up with this one instead: HICKORY ROAD, which many would likely judge superior to my initial effort.
There is more to be said on this topic, so I shall return to it later and explore specific genres of liturgical music in light of the above, including traditional chant and contemporary christian music.