Judith Durham! How could I forget? She has a truly unique, wonderful voice and the Seekers had such a good song selection.
To another post, I love Dionne Warwick’s voice, it is so soft, something.
To Judith Durham, the brother of Dusty Springfield wrote some of the Seekers’ songs like Georgy Girl. https://en.wikipedia.org/wiki/Georgy_Girl_%28song%29 (He wrote “I’ll never find another you” as well)
What some people may not know is that he and Dusty sang for the Springfields, so the Springfields were almost like an early incarnation of the Seekers, similar at least, but Dusty split and of course, she had a big effect on the music pop scene.
But I love the way Dusty Springfield sang for the original group, the Springfields;
https://www.youtube.com/watch?v=ilqKtJrs12w
Anyway, just my view.