Well--here I am! Firstly, the song is Noche de Ronda, not Ronde, which is probably why you had trouble finding it. Secondly, it is really a Mexican cancione, so it is generally performed on guitars or with an accordian, the verse being done rubato, the major melody being done in that Mariachi-like 3/4 time that they have--

I don't know the cha-cha version that you are using, but do know of a mambo/salsa version by Orlando Contreras and Daniel Santos on their album, Los Jefes--a cha-cha is basically a version of the mambo which is pretty much salsa, anyway--Good luck with your dance!