A quick marching band history question for everyone:

If you think back to many high school marching band performances from the late 1970s and early 1980s, it was common to see drumlines wearing aussies while the rest of the ensemble wore shakos.

What was the stylistic reasoning behind giving the drumline a distinct look? What where the typical visual design trends of the era, practical considerations, or some combination of factors?

I'd also be interested in hearing about any broader uniform and visual trends in marching bands during that period.

Thanks for the info!