I think EDM has extended it's scope well beyond anything that disco ever did in terms of it's versatility, so not sure it's really all that comparable. There is so much more variability in sounds with Dance Music now, that it appeals to different subcultures, scopes from small warehouse parties to festivals that are on par with the grandiosity of Coachella and Bonnaroo. Electronic Music has such an amorphous quality to it that we have gave it this term 'EDM', which is not even really a genre but more like an umbrella catch all term for extremely diverse array of sounds.