Watched this cracked video today (cued to the relevant part) - https://www.youtube.com/watch?v=u7iV-HZlMQM#t=196
Now I always take Cracked stuff with a huge grain of salt - but it seems that dancing movies were prevalent back then.
Was this a function of simply not having an alternative, or did something change culturally?
One reason might be that most dance movies today are typically directly targeted at and marketed to pre teen and highschool girls.