Apple’s iTunes music store will soon reach 10 billion songs sold since its inception in April of 2003, and is marking this accomplishment with a contest rewarding the purchaser of the 10 billionth song a $10,000 iTunes card.

While Apple’s iTunes took nearly three years to reach its first billion, it will soon surpass 10 billion songs sold since the online music service was introduced in 2003…

“iTunes changed the way you buy music, making songs and albums available for download, day or night. Seven years later, we’re about to celebrate our biggest milestone for music, yet — 10 billion songs downloaded,” states Apple’s website.

You can enter at the site without a purchase, BTW.

Apple celebrated 3 billion songs sold in July of 2007 after four years of sales. Thursday’s contest announcement reveals that sales trends since then have greatly increased. iTunes has taken only three years to make its 10 billion song milestone.

In many ways, iTunes has been a core qualitative change in entertainment communications – usually unmentioned by pundits who only focus on hardware and the software running on that hardware.

iTunes and the AppleTV serve the same function for programs, documentaries, I download from the Web and import into iTunes to be distributed throughout the house as required. It’s all simple and easy – as it should be. I don’t mind mentioning, as I often have to content providers, if you’re sensible enough to make your content available on iTunes the market for your intellectual wares is broadened and deepened so much more over making consumers search for it through the whole web.

Update WINNER: Louie Sulcer of Woodstock, Georgia. The 10 billionth song downloaded? “Guess Things Happen That Way” by Johnny Cash.