Rumors of an upcoming ABC special promoting both Grey's Anatomy and Private Practice have been confirmed! "Come Rain or Shine: From Grey's Anatomy to Private Practice" will air Wednesday, September 19 at 9 p.m.

Offering an in-depth look at the evolution of Dr. Addison Forbes Montgomery - from her struggles at Seattle Grace to her search for happiness in Santa Monica - this special is meant to prepare viewers for Private Practice.

More importantly, this special will feature the Grey's Anatomy music video made out of the song "Breathe In Breathe Out" by Mat Kearney.

The song is included on Mat's October 9 re-release of his hit album Nothing Left to Lose. Like previous videos from The Fray and Snow Patrol, the three-minute music video shows memorable scenes from previous seasons of the hit series combined with emotional key moments from Kearney's video.

Kate Walsh (left) has officially left Seattle Grace for Los Angeles, but Katherine Heigl (right) and her 10 terrific fellow Grey's Anatomy co-stars remain.

The special will also feature a first look from the new season of Grey's Anatomy. It should be great. In the meantime, check out our video section or just scroll down the page for a couple of two-minute preview clips from the premiere!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.