I have a collection of some hundreds of original CDs, which I have mostly bought during my numerous trips to Buenos Aires. Most of them are tangos, along tango there are valses and milongas.
Zivals store in Buenos Aires at the corner of Callao/Corrientes is a tango DJ’s heaven and has practically everything you can possibly imagine… I have spent hours browsing through their immense tango argentino music collection and listening to the music.
Besides that, there’s iTunes, TangoTunes and a lot more.