Joran Belar was a student at the Tenaran Music Academy prior to joining. Belar was a talented musician who had composed several works, including Untitled, To a Truth, and who played piano, syn lara, Vulcan lute, li'dswed, and Tellarite hollow bell line. Belar was also arrogant and egotistical, qualities which, in part, caused Doctor Foris Hajan to recommend dropping him from the Symbiosis Institute's initiate program. These concerned were overruled, and Joran was joined with Dax in 2284, following the death of the former host, Torias.
The joining created an unstable personality, manifesting itself in the grisly murders of three unjoined Trill, Jelim Niecta, Mehta Bren, and Dr. Hajan. Joran was killed by his intended fourth victim, Temzia Nirenn, in the presence of Verjyl Gard, a special investigator for the Trill Symbiosis Commission. (DS9 - The Lives of Dax short story: "Allegro Ouroboros in D Minor")
The Commission revised their records to show Torias Dax remained joined for six months while in a comatose state, thus covering up the failed joining with Joran. The Dax symbiont was also subjected to a procedure that would block all its memories of this joining. Those memories would not reassert themselves until 2371, while Dax was joined with Jadzia. (DS9 episode: "Equilibrium")