The Question
In an earlier version of your post, you had asked:
I've seen two different English translations and I'm wondering which one is more correct.
Other users commented and linked through to a related question that discusses the translation of the first line. However, that line does not touch at all upon the nue bird, as mentioned in your later question. I think a fuller exploration of the text and its translation could still help answer this question:
In the chant the "鵺鳥" is mentioned, which has been variously translated as 'Chimera bird' & 'Sterling bird'. What bird is meant by this, and is it the mythical Nue? And if so, then why would a symbol of ill-omen be included in a wedding chant, which should be a happy and blessed occasion?
Notably, translation is always a matter of moving data from one format to another, where the two formats are never entirely compatible. Translation is always lossy, one way or another, and in dealing with that loss and attempting to produce a cogent and attractive target text, translators may sometimes take a few liberties. The ideal is (usually) to express the intent of the source, even if that necessitates changes in vocabulary and structure.
To start, as I've often heard from literature professors, "go to the text itself". Let's look at the source Japanese and analyze that.
The Source: Taking It Apart
As sung:
吾【あ】が舞【ま】えば、麗【くわ】し女【め】、酔【よ】いにけり
吾【あ】が舞【ま】えば、照【て】る月【つき】、響【とよ】むなり
結婚【よばい】に、神【かみ】、天【あま】下【くだ】りて
夜【よ】は明【あ】け、鵺【ぬえ】鳥【どり】、鳴【な】く
遠【とお】神【かみ】恵【えみ】賜【ためえ】
This seems like an odd mixture of conventions from Old Japanese and Middle Japanese or later. Although we have five lines, this is certainly missing the ages-old 5-7-5-7-7 metered structure of much Japanese poetry. I'm familiar with the modern language, and I've studied the Man'yōshū for some time, so the oddness I perceive here might be because this poem actually represents a particular phase of Middle Japanese poetry conventions that I'm just not savvy to. Or, this poem could be a purely modern contrivance using Old / Classical words to evoke that sense.
That said, let's dive in.
Line 1
吾【あ】が舞【ま】えば
- 吾【あ】: "I", "me"
- 舞【ま】えば: the verb 舞う "to dance" in the 已然形【いぜんけい】 or "realis" form まえ, with the ば ending.
- The realis + ば had different meanings in earlier stages of the language:
- A reason for a decision: "because"
- A permanent precondition: "whenever
[VERB]
, then [some result]
"
- A contrary statement: "although
[VERB]
, then [some unexpected or undesired result]
"
- A momentary opportunity: "when
[VERB]
this particular time, then [some outcome]
"
- A listing of things that happened, similar to the modern use of し: "
[VERB]
, then [some other actions]
"
This last usage pattern only appears from around the Kamakura / Muromachi periods.
Considering the above, we could interpret 吾が舞えば in various ways.
麗【くわ】し女【め】
- 麗【くわ】し: "refined and beautiful"
- The modern term くわしい is more commonly spelled 詳しい, and refers more to "knowledgeable, knowing the details". This developed from the earlier meaning of "refined", with a focus more on "beautiful".
- 女【め】: "woman"
As a whole phrase, we'd expect the adjective to be in the 連体形【れんたいけい】 or adnominal form くわしき. However, くわしめ does appear as a set phrase in very old texts such as the Kojiki of 711-712.
酔【よ】いにけり
- 酔【よ】い: the 連用形【れんようけい】 or stem form of the verb 酔【よ】う, "to become intoxicated".
- にけり: a very old verb ending that expresses a kind of wonderment at something having happened.
- に is the stem form of completion auxiliary ぬ.
- けり is another auxiliary expressing a recollection of something in the past. This is probably a fusion of past recollective auxiliary き + あり (modern ある), the earlier copular "to be" verb (from which modern だ evolved).
- Breaking this down and putting it back together, the basic meaning is something like "wow,
[person]
got drunk / became intoxicated".
Line 2
吾【あ】が舞【ま】えば、照【て】る月【つき】、響【とよ】むなり
We'll skip the repeated 吾【あ】が舞【ま】えば.
- 照【て】る月【つき】: pretty straightforward, "shine" + "moon" → "the shining moon"
- 響【とよ】む: "to make a thunderous shaking sound; to cry out; to resound, to ring out; to be noisy; to throb painfully".
- Also found as どよむ in younger texts. Appears to be the mimetic word とよ or どよ referring to a lot of loud voices together, + suffix む meaning "looks like, seems like, behaves like".
- なり: Many possible meanings, which I won't list.
- Given the context and the usage at the end of the line, the most likely sense is an affirmative declaration, like modern "のだ". This なり could also have a separate sense of "reported speech" similar to modern "そうだ" on the end, but I don't think that meaning fits very well here.
Line 3
結婚【よばい】に、神【かみ】、天【あま】下【くだ】りて
- 結婚【よばい】: A visit to propose marriage.
- There is a common folk etymology described in various places online that derives this from 夜【よ】 "night" + 這【は】い "crawling, creeping" from the idea that someone is creeping into someone else's bedroom in the night. This is partly due to the 当て字 spelling of 夜這い.
Historically, this did have connotations of "to come calling (on the sly)". However, this よばい is actually the regular stem form of verb よばう, in turn just the iterative / repetitive / continuing form of 呼【よ】ぶ "to call", as the 未然形【みぜんけい】 or irrealis ("hasn't happened yet") conjugation yoba + iterative / repetitive / continuing auxiliary ふ.
So 呼【よ】ぶ "to call" → 呼ばう "to come calling (repeatedly, as when courting)".
- The rest is pretty straightforward.
Line 4
夜【よ】は明【あ】け、鵺【ぬえ】鳥【どり】、鳴【な】く
- 夜【よ】は明【あ】け: "the night opens" → "dawn breaks"
- 鵺【ぬえ】鳥【どり】: also known as 虎【とら】鶫【つぐみ】 or White's thrush, a particular kind of bird.
- You mention the translation "chimera bird".
鵺【ぬえ】 does have an alternative meaning of "chimera", as in "a mythical creature with body parts from different animals". However, the nue kind of chimera is quite specific, with the head of a monkey, the torso of a tanuki, the tail of a snake, and the legs of a tiger. There's nothing bird-like about that description.
The translator may have been taking some poetic license, as the nue chimera is also said to have a strange voice and call similar to the White's thrush. Or rather, the creepy nightime call of the White's thrush likely gave rise to the idea of the nue chimera. And given the Ghost in the Shell context, of a cyborg that is part human and part machine, the "chimera" term itself fits quite well.
- You also mention the translation "sterling bird".
There's nothing called a "sterling bird" that I'm familiar with. I suspect the translator may have confused the White's thrush with the related starling (not sterling). However, the starling doesn't make any particularly creepy or sad call, and it also doesn't call at night. I think this translation is just a mistake.
By way of reference, there's a short sound recording available here of the bird's call at night. It is indeed a bit eerie and creepy.
- 鳴【な】く: "to cry, to make a sound"
Possible renderings:
"The dawn breaks, the chimera bird calls"
"The dawn breaks, the thrush makes its creepy call" (more explicitly calling out the creepiness, which would otherwise be lost on readers who are probably unfamiliar with the chimera bird)
However, there's a double-meaning here. 鵺【ぬえ】鳥【どり】の is also a 枕【まくら】詞【ことば】 or a kind of introductory epithet, where the creepy sad call of the thrush is used as a metaphor for alluding to various things, including 心【うら】泣【な】き "crying on the inside", のどよい "silent weeping", and even 片【かた】恋【こい】 "unrequited love". (Relevant Kotobank page.)
Line 5
遠【とお】神【かみ】恵【えみ】賜【ため】
Wow, this line has a lot going on.
- 遠【とお】神【かみ】: this could simply be 遠【とお】 "far off distance" + 神【かみ】 "god, spirit".
- However, in Old Japanese, this compound didn't happen. Instead, we have 遠【とお】つ神【かみ】, where つ is the ancient possessive like modern の.
- 恵【えみ】: "blessing"?
- The kanji 恵 would suggest a reading of めぐみ, not えみ. I can't find any word えみ that's spelled with 恵. Instead, we find 笑み and 咲み, referring either to "smiling" or "blooming", from a root idea of "coming into fullness and opening up (such as fruit, or flowers, or smiles)". I suppose this could be interpreted poetically as "blessing", from the various senses of "fruition" that relate to "marriage".
- 賜【ため】: "receiving"? "gimme"?
This could be a sound shift from たまい, itself the stem form of verb たまう, an honorific for "to give (such as a superior to an inferior)".
Alternatively, this could be a sound shift from たまえ, the imperative of たまう. Similar in meaning to modern くれ.
On its surface, this could be parsed as a somewhat ungrammatical phrase meaning "the far off god gives a smile/blessing", or as a command/request, as "far-off god, give me a smile/blessing"
However, there's a deeper meaning going on here, riffing on a very ancient phrase.
とおかみえみため is the modern kana rendering of ancient と・ほ・かみ・ゑみ・ため (to po kami wemi tame), the names of five specific lines cut into the inside of a tortoise shell, which would then be roasted, and the resulting pattern of cracks on the outside of the shell would be "read" to divine the future.
Later, this phrase came to be used as a kind of incantation or invocation when praying for absolution.
(Entries at Kotobank and Weblio.)
In the context of this whole poem, this last line has two meanings -- one positive (the marriage with the god has received a blessing, or perhaps the speaker is asking for a blessing), and one negative (the speaker is praying for absolution for the sin of doing something awful, possibly the sin of co-mingling the earthly and godly and thereby sullying the godly).
Putting It Back Together: Possible Translations
吾【あ】が舞【ま】えば、麗【くわ】し女【め】、酔【よ】いにけり
吾【あ】が舞【ま】えば、照【て】る月【つき】、響【とよ】むなり
結婚【よばい】に、神【かみ】、天【あま】下【くだ】りて
夜【よ】は明【あ】け、鵺【ぬえ】鳥【どり】、鳴【な】く
遠【とお】神【かみ】恵【えみ】賜【ため】
Keeping it reasonably close to the source:
When I danced, oh how the beautiful woman became intoxicated
When I danced, the shining moon did thunder out
The god descended and came calling to woo
The dawn broke, the chimera bird made its sad call
O distant god, give grace
Straying more from the literal words of the source, in an attempt at something more recognizable as English-language poetry and to try to better approach some of what the original evokes:
I danced and oh but how the beauty swooned
I danced and oh the thund'rous shining moon
The god descended and came to woo
Daybreak's eerie chimera-bird call
By the gods' grace, may I be absolved
Back to the question
... why would a symbol of ill-omen be included in a wedding chant, which should be a happy and blessed occasion?
Ultimately, this isn't a wedding chant, so much as a snippet of a tale of forbidden love. As I understand it, the nue bird's call here isn't an ill omen per se (we're not talking impending disaster), so much as a recognition that things could never work out between a god and a mortal, and an allusion to the inevitable parting of ways. The last line's origin as a recitation for divination, and later as a broad plea for divine forgiveness, also makes clear that this is not an altogether happy and blessed occasion.
Note: This poem has 5 lines, and at first glance, it might seem to echo the structure of a five-line 短歌【たんか】. However, 短歌【たんか】 have a strict moraic structure of 5 7 5 7 7, which this poem notably ignores.
吾【あ】が舞【ま】えば、麗【くわ】し女【め】、酔【よ】いにけり (14 morae)
吾【あ】が舞【ま】えば、照【て】る月【つき】、響【とよ】むなり (14 morae)
結婚【よばい】に、神【かみ】、天【あま】下【くだ】りて (12 morae)
夜【よ】は明【あ】け、鵺【ぬえ】鳥【どり】、鳴【な】く (10 morae)
遠【とお】神【かみ】恵【えみ】賜【ためえ】 (9 morae, or 8 if not counting the final ~え)
Or, breaking it down by comma-delimited phrases,
- 5 + 4 + 5
- 5 + 4 + 5
- 4 + 2 + 6
- 4 + 4 + 2
- 9 (or 8 if not counting the final ~え)
Definitely not a 短歌【たんか】.