The music you choose for your Hawaiian Luau can be either traditional Hawaiian music or fun beach party music. They both will work great. Just make sure you're consistent and design the other details of your party to mesh with the mood set by the music. For example, if you select traditional Hawaiian music I would choose low-key, natural decorations when Setting the Stage. But if you feel like hosting a fun, beach party type Luau, I'd go with beach party music and pull out all the campy decorations such as the plastic hula dolls and cardboard palm trees.
Traditional Hawaiian Music Sources
Don Ho Gold - Many mainlanders consider the music of Don Ho to be the most representative of the Hawaiian sound.
Hawaiian Music and Hula Archives - You can't listen to the music at this site, but it's an amazing directory of very beautiful and poetic Hawaiian lyrics.
Beach Party Music Suggestions
The Surfaris - This band is most famous for the tune "Wipeout."
The Beach Boys - There's no way you could hold a beach party without some music from this band!
Blue Hawaii - This classic soundtrack from the movie by Elvis Presley will add a rocking Hawaiian ambience to your luau.