One of my favorite contemporary Hawaiian music artists is Robi Kahakalau, a.k.a. Sistah Robi.
To get a feel for what her mellow music is like, you can sample the song "Ku'u Mau Lei Onaona" (which means "beautiful scented leis") from the album "All I Want."
Here's her singing "Dreamland":
Robi Kahakalau, a.k.a. "Sistah Robi."