There is the afro-cuban rumba that mostly has percussion only, plus maybe voices(s), maybe not.
And then there is the "ballroom rumba". Maybe this is what you mean if it is suited for cocktail parties .
Musically this western rumba is the (mostly degenerated) child a slow cuban son. When the first son was published in the US, they thought it would be better in terms of marketing to use a well-known genre name so they replaced the word "son" by the word "rumba".