The song was written by the System's David Frank and Mic Murphy.

In May 1987, the song reached number 1 on the US Billboard R&B Singles chart, spending one week on top.

I spent the better part of three days working on different ideas and options and I remember wondering whether I was wasting my time.

It needed a link between the verse and chorus so we worked out the “hang a sign up on the door” section.

Our manager and record company didn’t think it should be first single but Mic and I did and we won out on that, thank goodness.