What's the stylename/name of this kind of shirt?

You know the shirts back in the 80’s or was it the 60’s where the neckline of the shirt is cut to make it bigger and the girls would where a tank top underneath the shirt and one side of the shoulder would be shown. The shirt would be slide to the sideways and the neckline is so big that it would show your shoulder.

It’s a shirt something like those aerobic people would wear when they’re working out back in the 60’s/80’s/90’s(I really don’t remember which specific era)?