If you want music to play when people look at your webpage, the simplest way is to just upload a song (any file host will do) and use html coding in your webpages to embed a simple player and set it to repeat/loop the song. When people hit your page, the song will start to download - when it's finished, it'll play & repeat. Or if you know how, you can go the streaming route and it'll only download a buffer before playing, meaning less delay time.
If you're asking whether people can listen to songs without having to spend the time waiting for a file to download at all, there's no way to do that.
to be specific: I would like to have the song uploaded, but it should only play if the people click on the play button, just like with average WMP.
(not that the site plays the song on and on)