No truer example than to hear Joni Mitchell within the last 20 years singing some of her songs from the 70s. Sad.
In the 2003 movie Love Actually, when the wifenmom leaves the room to react privately to having discovered her husbands infidelity on Christmas Eve with the whole family, the soundtrack played a cigarette-damaged version of Jonis Both Sides Now. Jonis wrecked, husky contralto was almost as tear-jerking to me as the betrayed womans quickly wiped tears, knowing that she and her cheating husband would be taking their excited kids to perform in their Christmas pageant at church in a few minutes, and she must put on a brave face for their sake.
Well this gal that was speaking was just 27....