The policeman, Pol Snr Sgt Maj Nikom Jeanyuen, 42, went to the Sarapan Plaeng bar on Pitak Rd, not far from the circle, with three friends.
As they sat there at about 1:45 am, a member of another group in the bar, believed to be assistants to a local village headman, asked for a certain song to be played on the stereo.
The bar owner refused to play that song, and the group promptly walked out.
Not long after, the group returned in a car and the furious music lover opened fire with a homemade shotgun pistol, firing five shots at close range into the bar.
Sgr Maj Nikom was hit in the head, neck, chest, arm and stomach but survived. He was rushed to Bangkok Hospital where he is still under treatment.
One member of the shooter's gang, 28-year-old Supanet Sukgaew, from Surat Thani, has been arrested. He has admitted to police that he was driving the car but denies being the shooter.
Police have identified another member as Wutthichai Songsri, 33, from Trang, currently out on bail on a charge of attempted murder, laid against him last year.
Police are trying to identify another three members of the gang.