The series was set in Los Angeles and, more often than not, inside a jazz club called Mother’s. The storyline essentially centered around Gunn solving his client’s problems, which always involved his having to deal with an assortment of hit men, hoodlums, and assorted “hip” characters found on the jazz scene. He was often aided by his personal friend and confidant, police Lieutenant Jacoby (Herschel Bernardi). Although Gunn often had to endure many thrown fists, he himself did not advocate brutality, and violence was not a feature of the series. In the end, the crime was always solved, the criminals were behind bars, and Gunn was shown relaxing at Mother’s, where his girlfriend, the vocalist Edie Hart (Lola Albright), was the main attraction.

The style of Peter Gunn has been described by some viewers as borderline parody. The dialogue was delivered in a hip, deadpan fashion, and at times the series seemed to be poking fun at more conventional private-eye series. Blake Edwards attributed the critical success of Peter Gunn to the series’ tendency to be somewhat over the top. The success of the show spawned many similar private detective dramas in the late 1950s and early 1960s, such as Philip Marlowe and Richard Diamond.

An important ingredient in the show, one that provided its unique character, was the music of Henry Mancini. He provided a new score for each episode, and when released on the RCA label, the two albums The Music of Peter Gunn and More Music from Peter Gunn became best sellers. (The “Peter Gunn Theme” continues to be played on mainstream radio and has even been used as the vehicle for modern rock versions.) Mancini’s music was an integral part of the show’s action, and here too it set the precedent for shows that were to follow.

The show lasted for only three seasons, but by stressing style and sophistication Peter Gunn caught the attention of many viewers. The combination of the main character’s smooth, stoic demeanor, together with Henry Mancini’s outstanding jazz themes, worked to leave a lasting impression in the minds of fans.