Sir Horstmanns Jazzband is a South Jutland jazz orchestra based in Aabenraa, playing traditional New Orleans-style jazz. The band was founded in 1991 by employees of the Sønderjyllands Højspændingsværk power plant, where three brass players joined forces with four other jazz enthusiasts. Bandleader and clarinetist Gottfried "Gøje" Horstmann has guided the group's musical direction from the start, with the motto "it must swing". The band has released three CDs and has performed in Denmark as well as Germany, Latvia and France.
Sir Horstmanns Jazzband performed at Livø Jazz Festival 8-10 August 2025.
The band participated in the reopening of Aabenraa Jazztival on 28 September 2024 - the festival's first edition in five years after the corona break.
The band played for dancing at New Orleans Jazzklub in Apotekerhaven in Sønderborg as part of the All That Jazz collaboration.
