Rabbi: The words to the original song can be found on the web, if one wanted to find it. When you see the original words, it really doesnt matter how “pure” one makes it. If you know the original, you wouldnt want to sing ANY words of tehillim to that tune.
Others:
The bashing of individual singers, mentioning them by name, and calling them all sorts of nasty things is as least as assur as the music they claim is assur. Was a heter obtained to name an individual and drag his name though the mud?
You dont like the music of an individual? His (her if your a woman) voice? His tunes? The music chosen to accompany the tune? The lyrics. The chosen venues for performing? Fine. Dont like it, dont buy it and dont listen to it. To drag the name of someone who isnt even alive through the mud, is disgusting, at best and probably violates numerous halachos of lashon hara.