Improving sound quality?

[1LOVE-T]

There's a song I've recently downloaded that has no recorded version of it. It's the best quality I've found, but unfortunatly it's still not very..listenable quality. I was wondering if there was a way to clean up the song (maybe on audacity, which I have) by lowering the sound of the piano and increasing the sound of the voice, as well as improving clarity? Btw, this is one file, not recorded seperatly.
If anyone can help, thank you in advanced

[visionfactory]

You can use Goldwave, I love Goldwave it's really useful you can use its Noise Remover or play with the Equalizer or the Karaoke function

I'll explain you why I said you can use the Karaoke function:
Every song can be split into 2 tracks
In the first track generally are the echos, noises and backing vocals
In the second track you can find the main melody and voice

So cancelling or reducing the volume of the 'first track' you'll got to listen more to the vocals that's it

[1LOVE-T]

Where do you find the karaoke function?