Mumford & Sons, Old Crow Medicine Show, and Edward Sharpe & the Magnetic Zeros all chug through town via the Railroad Revival Tour this weekend. The three bands are traveling in vintage rail cars on a six-date cross-continental jaunt, performing together, practicing in the cars, and generally trying to make a congenial go of things. There's a similar acoustic vibe at work here, with Mumford and Old Crow favoring old-timey, throwback folk-rock and bluegrass tunes, and your third band offering up blissed-out Cali folk. Christian Letts, guitarist for Edward Sharpe, says some of the onboard jam sessions will be recorded, and he expects that the live shows, including this weekend's, will feature a bit of onstage collaboration between acts as well. Originally booked to go down at the Railroad History Museum in Chandler, the venue switched to an outdoor space in Tempe a few weeks ago. As a result of the new digs, the promoters added more tickets to what was previously a sold-out event.