M Squad was a successful police drama that ran on NBC from 1957-60 that featured Lee Marvin as Lt. Frank Ballinger, a top detective for the Chicago Police & their special unit, M Squad.
Lee Marvin(during his TV days)not only played the lead, but also narrated the episodes leading the viewers throughout the episodes. The show originally was criticized by the Chicago Police Dept. as well as then Mayor Richard J. Daley for showing the city in a less than favorable light, as well as what they consider an "unrealistic" approach to police procedure.
At the show's 2nd season, a jazz-oriented theme music replaced the original title tune was composed by Count Basie.
The show is now enjoying a return to Chicago TV after many years now being seen by a new generation of potential fans, myself included!