Why do vocal harmonies of older songs sound have that rich, “airy” quality that doesn’t seem to appear in modern music? (Crosby Stills and Nash, Simon and Garfunkel, et Al)

Question

I’d like to hear a scientific explanation of this!

[Example song](https://youtu.be/C7HP9Xkim9o)

I have a few questions about this.
I was once told that it’s because multiple vocals of this era were done live through a single mic (rather than overdubbed one at a time), and the layers of harmonies disturb the hair in such a way that it causes this quality. Is this the case? If it is, what exactly is the “disturbance”? Are there other factors, such as the equipment used, the mix of the recording, added reverb, etc?

EDIT: uhhhh well I didn’t expect this to blow up like it did. Thanks for everyone who commented, and thanks for the gold!

In: Physics

Answer 1

Part of it might have to do with the loudness war and songs being mastered for shitty audio gear now days. The loudness war is artist wanting their music to be mastered louder and louder, which results in less fidelity in the song because its all kinda jammed up there rather than using the full spectrum.