You've all heard about the happy birthday ruling. This spun off a discussion in our office (none of us are lawyers). If I copyright the lyrics to a song in English, does the copyright apply if the lyrics are translated into another language?
Yes because the translated song is a derivative work.
17 U.S. Code § 103
(a) The subject matter of copyright as specified by section 102 includes compilations and derivative works
Derivative works is defined in § 101
A “derivative work” is a work based upon one or more preexisting works, such as a translation...
FWIW, § 102 says
(a) Copyright protection subsists, in accordance with this title, in original works of authorship fixed in any tangible medium of expression, now known or later developed, from which they can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device. Works of authorship include the following categories...
(2) musical works, including any accompanying words;
It depends. First, fair use does cover such things as parody, satire, criticism, critique, and educational purposes. The copyright for a song resides normally with the artist's performance of it (aka arrangement) and includes both the musical qualities and lyrics, not solely one. The United States uniquely leaves the copyright with the author, who gets paid no matter which way it's sung. Elvis Presley, for example, did not write "Blue Suede Shoes" or "Hound Dog" but in fact, heard them and performed them in his own unique way, and people paid him to hear him sing his version of the song. It was common practice in the States to record songs in multiple genres and see what stuck.
Due to the nature of music, especially when fitting melody with lyrics, the songs can vary wildly in nature. A good way to see this is to look at Disney's own translations of their songs. There is a significant fan effort to take the existing foreign translation and provide a back translation in subtitles as a way of helping people understand languages. Because the songs have to keep with the soundtrack from the movie, they tend to shift in quality between translations. The song "Out There" and its German equivalent "Ein Mal" from Hunchback of Notre Dame are fundamentally different songs set to the same tune (the lyrical difference is that in English, the singer wishes for his one chance to go out into the world. In German, he's wishing for a time where he can tell the story of his one adventure out, as "ein Mal" is "one time," but the song frequently plays with it and uses the phrase "es war ein Mal" at several points in the song, which literally translates to "it was one time" but figuratively reads as "once upon a time").
Given that nature, how much of the original idea of the song in question is preserved in a translation can vary wildly depending on the translation and the flexibility of the language to fit the lyrics. For example, while a Japanese song about about a Dream (Yuma) translated into English could in theory preserve the meaning of the song as Yuma/Dream hold the same meaning in all contexts (either subconscious weirdness that occurs when you're sleeping or hopes, aspirations, or goals), provided minor changes to words that don't line up that perfectly (and this one to one translation of all possible meanings is rare in languages). However, it might not translate into another language where the meaning of "dream" does not hold one of these definitions. This is important because under the law, ideas cannot be copyrighted. There is nothing unique about the phrase "Baby, Oh" that can be protected by copyright, but the unique way Justin Bieber says it can be. Thus, as there is a significant likelihood that a song's idea will be fundamentally altered by its translation into a foreign language, the song qualifies as being a transformative piece and thus falls under fair use (legally speaking, there is nothing stopping Weird Al from making any of his parody songs without permission. He's just a nice guy). While your musical performance might be the same, the changed idea means it is a transformative, not a derivative, work.
Another example can be seen in Nena's classic hit "99 Luftballoons" which was translated into English (and recorded by the band in English initially) as "99 Red Balloons" Since the word "Luftballoons" literally translates to "Air Balloons" and can just as easily mean "Balloons" already the song had an extra part that needed to be covered, hence the sudden color in the title. While the original band performed the original English recording, most English speakers and the band themselves prefer the German version. The Ska Band Goldfinger's 2000 cover of Red Balloons seems to be the preferred English Version. As noted, the song is poetically translated, meaning that the spirit of the song (that 99 Balloons triggered a nuclear war) was preserved at the sake of the narrative. What causes the war in the German versions isn't the Balloons themselves, but the jet fighters sent to investigate the balloons as a UFO. Concluding that they are harmless, decide to have some fun and launch missiles at the Balloons... The East Germans see this and believe the West Germans are rattling sabers and fire back at the jets. This leads power hungry war ministers (presumably on both sides) to declare war that lasts 99 years and destroys everything... again, all over balloons.
In the English versions, the balloons set off early warning systems in the United States and indicate an impending Soviet attack (laugh, but unknown at the time, something similar happened in the Soviet Union). This triggers what the U.S. believes is a second strike retaliation that again starts off a war that destroys everything. Keep in mind that in U.S. politics at the time, being the aggressor was quite taboo (the movie "Day After" lost military funding after the film refused to say who "shot" first, because the whole point is that to the survivors of this conflict, it really didn't matter). So whereas the German version blames the NATO powers for some dude-bro antics of their fighter pilots leading to power hungry politicians to start the war, the English version blames a justifiably panicked military doing what they thought was best, given the situation. The first was a deliberate war, albeit subtle, while the second was an accident (and as Nena felt, a bit more blunt in message).
Again, nothing problematic with the copyright here, and both performances are sold to this day and used for commercial purposes.
In all copyright cases, of course, the decision to pursue a suit is more monetary than morality. Keep in mind, plagiarism is not a crime, just very bad. Claiming you wrote a pop song is perfectly legal up until you start making money off that claim, and even then, it has to be damaging enough to catch the copyright holder's eye.