Yeah, that Pearl Fishers duet gets to me every time. I think it was featured in the movie Gallipoli.
Funny thing about opera -- there I especially enjoy the voices because when I don't understand the language, the voices are like musical instruments, universal in appeal.
Problem with lyrics is sometimes they can ruin the music or just get outdated. Worst thing is if you hate what the lyrics say but love the music.
Most extreme example probably is Deutschland Uber Alles when it became a symbol of the Nazis who, like so many music hijackers, applied their lyrics to previous favorite music (from Haydn, I think).
Dixie was written in Ohio as a vaudeville tune but became the anthem of the Confederacy, offending some people while rallying others.
Often composers are eclipsed by lyricists, e.g., Amazing Grace, America the Beautiful, and Battle Hymn of the Republic.
Once in awhile great music and words are written by the same person, e.g., The Rose by Amanda McBroom.
Sometimes it's hard to tell where music really comes from, e.g., old folk melodies supposedly incorporated into some classical music. At least the melodies are preserved no matter who originated them (and sometimes they are improved by subsequent interpretations).
Whatever and whichever, music is the gift of the gods.
