"Since the death of Terry Kath in 1978, the vocals for live performances of "Make Me Smile" were handled by Bill Champlin, who joined the band for the recording of Chicago 16, until he departed the group in August 2009. On shows that Champlin did not attend, Robert Lamm sang the lead vocal. Champlin's replacement Lou Pardini has now taken over the singing of "Make Me Smile"."
This one was quite a project when we at Paragon learned it a few years ago. Denis is on vocals, Mark D is on horns. We do the full studio version, not the shorter radio version.
For your enjoyment, here's a live version of Chicago: