Please identify this distinctive bird song

Greetings all! Just logged in here for the first time to see if any of you friendly folks can identify a bird from its rather distinctive song. For several years now I've heard this delightful, consistent "tune" in various places around our neighborhood (Chelsea, Victoria). Unfortunately, I've only ever had the vaguest glimpse of this bird, and never while it was actually singing.

With only its distinctive song to go by, I've listened to countless bird recordings, the closest of which was the Butcherbird. However, none of the recordings captures the distinctive tune that this one makes.

Today was the first day I heard it close enough to home for me to grab my MP3 player and capture a recording. It was competing with a rather raucous Wattle Bird, but I managed to separate a few seconds that includes the distinctive, and fairly consistent, "tune".

I've uploaded a couple of small (82Kb each) .MP3 files to a temporary area of my web site:
http://www.fieggen.com/_temp/20090616_ButcherBird1_Distant.mp3
http://www.fieggen.com/_temp/20090616_ButcherBird2_Close.mp3

Note that I've tentatively called the files "Butcherbird", but please don't let that sway your judgment if you feel it could be something different!

Thanks in anticipation!