It’s official! Apple this evening sent out email invitations to the media to attend a special event at Moscone West in San Francisco on September 5th at 10am PDT.

“The Beat Goes On,” is a song released by Sonny and Cher in 1967. The phrase also appears on Sonny Bono’s tombstone.

In addition, and perhaps more relevant to Apple’s event (let the speculation begin), the phrase also appeared in The Beatles final press release, issued April 10, 1970:

Spring is here and Leeds play Chelsea tomorrow and Ringo and John
and George and Paul are alive and well and full of hope.
The world is still spinning and so are we and so are you.
When the spinning stops — that’ll be the time to worry, not before.
Until then, the Beatles are alive and well and the beat goes on, the beat goes on.

The albums depicted in Apple’s Cover Flow-inspired invitation artwork (from left to right):
Keane – Under the Iron Sea
The Flaming Lips – Yoshimi Battles The Pink Robots (Thanks “slayerfran” and “jtmportland”)
Beastie Boys – The Mix-Up
- Apple’s iPod silhouette artwork with “September 5″ text
MIKA – Life in Cartoon Motion
Jack Johnson – In Between Dreams
• Sonic Youth – Rather Ripped (Thanks “Tribhanga”)

It’s been rumored that Apple will use the event to debut next-gen Mac OS X-based iPod(s), add TV shows and feature films to iTunes Stores outside the U.S. (UK, France and Germany are the most likely candidates), and perhaps “One more thing.”

For those inclined to some sleuthing: the first songs from each album on Apple’s iTunes Store (in the same left to right order) are as follows:
Atlantic, Fight Test, B for My Name, Grace Kelly, Better Together, Reena

The top songs from each artist on Apple’s iTunes Store (in the same left to right order) are as follows:
Somewhere Only We Know, The W.A.N.D., Fight for Your Right, Grace Kelly, Upside Down, Kool Thing

So, obviously, Grace Kelly will be there. wink