They were in one of the University of Otago's recording studios creating a 10-track CD and DVD which should hit the market in time for Christmas.
Organiser Alethea Taylor said most of the musicians had not recorded in a studio before and found it challenging as "live audiences were more forgiving" compared with machines which "pick up on every tiny slip".
The full jazz band and seven-piece Hoodoo Voodoo spent all day Wednesday and yesterday morning recording tracks.
Craig Storey will complete post-mixing, arranging and physical production, "ready for Santa's sack".
Three pupils also filmed the proceedings, from set-up through to performance, which will become part of the package.
Motivation for the project came from the jazz band winning best overall band and the best drummer award at the national secondary schools competition in Blenheim in August and Hoodoo Voodoo winning the youth competition at the Queenstown Jazz Festival in October.
Ms Taylor said with five band members finishing school at the end of the year, it was appropriate to record a CD before the band changed.
The school funded the venture and would be primary contact for purchase of the CD set, which includes a range of jazz styles, from swing to funk and jazz rock.
