In further celebration of the re-launch of our favorite Led Zeppelin-related iPhone app, the 'Live Dreams' photo gallery, Ultimate Classic Rock is giving you the chance to win another exclusive in-concert photo of the band from photographer Larry Ratner.

This portrait features lead singer Robert Plant in full wail during a performance of 'Black Dog' from an Indiana concert from 1975.

You may, or should, also know we're already giving away an excellent photo of Jimmy Page circa 1973. (There's still time to win that one, as well.)

If you haven't already checked out the ‘Live Dreams’ app, maybe seeing these two great photographs will inspire you to do so. 'Live Dreams'  lets you carry a boatload of Ratner’s exclusive live photographs of Led Zeppelin around wherever your iPhone or iPad goes.

There are also essays dedicated to his memories of shows from various cities and years, and information on how to purchase print versions of the photos. You can get more details on the app right here.

Ratner's provided us with a particularly detailed account of the song being performed while this photograph was taken: "Robert Plant lets his voice sail during 'Black Dog,' at Indianapolis in 1975. The song was inspired by two Blues icons;  Muddy Waters and Peter Green. The actual Muddy song, 'Electric Blues' was the tune that sparked John Paul Jones' idea for 'Black Dog.' The other Blues band that influenced this Zeppelin super-hit was Fleetwood Mac's song, 'Oh Well,' highlighted by Mac co-founder and Blues guitar icon Peter Green.

Jimmy Page would later perform 'Oh Well' with The Black Crowes on their 1999 tour. The title came from a nameless black dog that wandered around the Headley Grange studios during recording. On the studio recording of 'Black Dog,' Robert Plant's vocal was recorded in just two takes. It was one of his most memorable performances."

Just like the Page giveaway, the winner will get the print on an 11×14″ matte, signed and numbered. All you have to do is sign up using the form below.

Led Zeppelin - Robert Plant Exclusive Photo Giveaway

Enter your e-mail address for a chance to win an exclusive photograph of Led Zeppelin's Robert Plant from the 'Live Dreams' app and UltimateClassicRock.com. Contest ends September 30, 2011. Click here for official rules.