Kevin from tranzcontinental.com After playing a long show Thursday, Fleet Foxes tweeted “Thanks Ann Arbor, we needed that!” Occasionally bands will say they enjoy a particular show more than others, but Fleet Foxes frontman Robin Pecknold seemed sincere when he said “This has been one of our favorite shows, ever.”   Hill Auditorium in Ann Arbor, Mich. is a spectacular venue in itself, its incredible acoustics reverberating around its shell shaped interior, giving the harmonizing indie-folk group the acoustics their sound deserves. I’ve been told that singing on the stage at Hill is a unique experience, that as the sound leaves the singer it goes out into the dark abyss…