while similar, disco leans more pop and funk leans more soul (plus a heavier bass focus). dufus wasn't able to detect the soul because the dutch don't have those. 
I like to separate them in the sense that funk, traditionally, had a black power/pro-black empowerment mantra. Whereas disco mostly was just rocking your balls and tits off. There’s no empowerment, for the most part, besides Diana Ross records. Whereas funk was empowerment distilled.
Disco borrowed heavily from funk so it gets even murkier but a lot of it feels like an attitude.
