27-year-old Damien O'Brien from Kilmacow received serious head injuries in the incident on John Street in the early hours of last Saturday morning.
He was transferred to Cork University Hospital where he died yesterday.
A post mortem is due to be carried out there today.
A 25 year old man was arrested last Sunday and held for questioning before being released without charge, a file is being prepared for the DPP.
Damien's fellow musicians, bandmates and friends have been paying tribute to him.
Gardaí say their investigation is continuing.
They're appealing to anyone with information or who may have witnessed the incident to contact them on 051 305300.