info from wikipedia:
"Long Cool Woman in a Black Dress" is a song by the rock and roll group The Hollies. It was released on February 1, 1972, as a single on the Parlophone Records label.
The song's first-person lyrics tell a story of an FBI agent (the narrator) who is scouting a speakeasy in advance of a raid. Prior to the police's arrival, the narrator meets the "long cool woman" of the title, a singer at the bar described as "5'9", beautiful, tall", and immediately falls in love with her. The raid results in a shootout during which he protects her. The narrator is given congratulations by the District Attorney ("the DA") and, presumably, a relationship with the woman when he gets legal immunity for her.
It was released soon after Allan Clarke, who was featured on both lead guitar and lead vocal, had left the group. It appears on their album Distant Light (1971). As the group had just left EMI/Parlophone and signed with Polydor, they did not promote the song. However, it became a No. 2 hit on the Billboard Hot 100 charts and No.1 on Cash Box in the United States, their most successful single there, it was also No.1 in Canada. It was inspired by, and in the style of, the rock and roll group Creedence Clearwater Revival. On being reactivated by EMI in Britain a few months later, it reached No. 32 on the UK Singles Chart.
The song is notable in that it features Clarke playing rhythm guitar, something he rarely did. Clarke came up with the signature guitar rhythm that opens the song. In the light of the song's success, Clarke rethought his solo career and rejoined the group in 1972.