Offered is a brand new tune featuring Fall Out Boy's Patrick Stump and fellow Chicago brethren, Lupe Fiasco. Here's some words from Patrick on how it all came about:

“This City” prominently features fellow Chicagoan Lupe Fiasco, and Stump said his relationship with the rapper goes back several years. “Before Food & Liquor came out he and I were talking about working on something together. I ended up producing the song ‘Little Weapon,’ for his The Coolrecord,” he said. “I actually wrote the hook for ‘This City’ with him in mind before I decided to use it for Soul Punk, so when the label asked me if I'd be interested in doing a remix with an MC he was the only real way I'd say yes.”

Source: The LupE.N.D. Blog