The Eagles and the Doobie Brothers -- one-third of the six bands performing at this summer's Classic East and Classic West concerts -- are extending their run together with a newly announced show in Seattle.

Billed as the Classic Northwest, this double bill will take place Sept. 30 at Safeco Field, home of the Seattle Mariners. Tickets go on sale Aug. 5 at 10AM PT.

On July 15, the Eagles performed their first show since the death of founding member Glenn Frey as part of Classic West. They were joined by Vince Gill and Frey's son Deacon for the Dodger Stadium performance, which featured tributes to the late Frey, including a guest spot by his longtime friend Bob Seger.

In addition to the Doobie Brothers, Fleetwood Mac, Journey, Steely Dan and Earth, Wind and Fire played at Classic West. All six bands will join forces again on July 29 and 30 for Classic East, which takes place at New York's Citi Field.

Eagles guitarist Joe Walsh is also currently scheduled to perform a solo show on Sept. 30 -- the same night as the Eagles' Classic Northwest performance -- at the House of Blues in Las Vegas. That's a 17-hour, 1,121-mile road trip or a two-and-a-half-hour flight, according to Google Maps.

So unless he rearranges his plans, Walsh may need to call Phil Collins, who famously played in both London and Philadelphia on the same day during Live Aid ... or get a hold of a Maseratii that does a heck of a lot more than 185.