“What are some benefits and drawbacks of singing songs in their original language, when most of the audience cannot understand the text? Are these issues different if sung in a worship service vs. in a concert setting?”
The heart of a song is its text—the foundation on which melody is composed, voicings are built, and interpretation is shaped. But while words carry the up-front content of spoken language, studies show tone of voice and body language conveying more than the actual words. Up to 90% of communication is considered non-verbal. Music and singing add still more elements to that. The text remains prominent, but becomes one among several parts of what and how a song speaks.
Song translations from many languages and cultures are a rich part of Christian heritage worldwide. With that, however, parts of a song’s full musical /textual language (accuracy, flow, nuance, character) are virtually always reduced in translation. Sometimes it is minimal, but other times the changes are simply too much to preserve the heart of the song. The vibrant Wana Baraka (East African) or intense crucifixion-wail of Indodana (South African) could hardly convey more than a skeleton of their native essence in English words and phonetics! Nor does a Russian setting like the familiar Blagoslovi dushe moya ghospoda (Ivanoff) speak the same majestic solemnity in its lighter / thinner English form of Bless The Lord, O My Soul.
Paul’s admonition (I Cor. 14:15) to sing “with the spirit and with understanding” speaks from a different context, yet is pertinent here. Much of understanding naturally includes one’s own language. Yet, just as touring choirs find English songs connect with audiences in other countries (often with translation aids), some in their languages can also connect with us. The ratio of the “spirit / understanding” elements may flex in different settings, yet still speak potently. Music speaks both with, and beyond, its immediate text, bringing spirit and understanding together. As with much of life, key operative words here are “appropriate balance.”
As for differences if sung in a concert vs. a worship service? That should really be another topic! For purposes here—a concert not overtly projected as a worship service normally has more implicit latitude on various levels, including language choices. Music is a timeless bridge-builder across cultural and language barriers, and usually speaks most overtly and deeply in the language, musical voice and nuances of its origin. Whether in a concert or more specific worship setting, at times a spoken or written translation may open an equal—or stronger—window into the heart and fullness of the song than a translation actually sung. But, sacred music sung in any context is still sacred, and should engage and speak its sacredness wherever performed.