Qtrax – the legal, ad-supported free music download site – will begin its worldwide launch in October, starting with the Asia-Pacific region.For starters, it will operate in China (including Hong Kong), Taiwan, Philippines, Indonesia, Singapore, Malaysia, Australia and New Zealand. The official date is Oct. 29, a Thursday. By year’s end, it will officially launch in the United States, Canada and the United Kingdom, though it already has been available as a 1.0 “preview” download in the U.S.It appears to be available