Audio: Prince & The NPG "Old Friends 4 Sale" (2012 Rehearsal)

With his "Welcome 2 Chicago" residency kicking off in the Windy City tonight, Prince has been in full-on promo mode, appearing on ABC's "The View" and debuting a new song on a Chicago radio station last week.  This weekend he popped up on stage during Mary J. Blige's performance at the I Heart Music festival for to back her up on guitar for "Sweet Thing" and a duet of his classic ballad "Nothing Compares 2 U."  This morning, Prince released a stream of his band rehearsing the fan favorite "Old Friends 4 Sale" with a massive horn section.

Take a listen after the jump

The slow, jazzy tune dates back to 1985 and was left off of the soundtrack to Prince's second film Under The Cherry Moon, despite appearing briefly in the film.  Reworked in the early 90's, the song remained unreleased until appearing as the title track to 1998's collection of previously unreleased songs, The Vault... Old Friends 4 Sale.

If Prince is pulling out gems like these from his catalog for these "Welcome 2 Chicago" shows, we're extremely jealous of Chicago!

Watch Prince's guest appearance during Mary J Blige's I Heart Music festival appearance below!

Spotted @ DFB