Here’s a little recording I made in Kauai in April 2012:
I later learned it was a white-rumped shama. The shama is popular for its song—we heard this bird well before we saw it—and inspires a quite devoted following in some quarters.
Copsychus malabaricus is a type of thrush native to south and southeast Asia. It was first introduced to Kauai by Alexander Isenberg in 1931 (presumably this is the son of beloved sugar baron Paul Isenberg). The particular subspecies on the islands is C.m. indicus, found from east India and Nepal to northwest Burma.
In Asia, there are whole groups devoted to the bird. Singapore, especially, has an active set of shama enthusiasts raising them, sometimes catching them in the wild, and entering birdsong competitions with them.
To see what a shama looks like, the photo below (posted on Flickr by Chris Thomas), gives a better view of one of these birds than the less-than-stellar iPhone snap I filed with that audio clip.