Yes they could sing. As Gordon's wife said " that general era as "the era of harmonies", 60s through 70s,"
Today one group that can sing with no autotune is Foxes and Fossils:

https://www.bing.com/videos/riverview/relatedvideo?q=foxes+and+fossils+california+dreaming&mid=2962D432EB8C5A8C3AED2962D432EB8C5A8C3AED&FORM=VIRE


Why is it that doctors call what they do 'practice'?
If flying is so safe, why do they call the airport, the terminal?

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware