Redirection Help Me!!!

hello,

how can i redirect? i have a website that provide chords, so have a url like this below:
http://www.website.com/chords/chords.php?id_artist=189
i wanna change to:
http://www.website.com/chords/andy-park

I have lots of artists with differents id's

I tried:
RewriteRule ^cifras/andy-park$ /chords/chords.php?id_artist=189 [L]

the problem is: how can i redirect automatically, cause i had to specify it.

It's an example in this page:
http://www.pegacifras.com.br/generos/internacionais/

thanks
Rodrigo Zem