Disco comes from blacks and has influences of funk, soul music andsalsa, whichalso have their origins in black culture.Techno is a branch of electronic music which originated amongst black Americans in Detroit. House music is also another branch of electronic music which was created by FrankieKnuckles, ablack American living in Chicago.There is some European influence in House music as Knuckles mixed disco and European synthpop together to create the sound.

Here are some links for a more indepth history of the various genres.

http://en.wikipedia.org/wiki/Disco

http://en.wikipedia.org/wiki/Techno_music#Origins

http://en.wikipedia.org/wiki/Frankie_Knuckles

http://en.wikipedia.org/wiki/House_music