The North Theatre is explicitly referred to as an odeion in a late 2nd century inscription that ran along the architrave of the scaenae frons (decorative background of the stage). It was thus used to stage music and poetry recitals.

However it was originally built as a bouleuterion, used for meetings of the boule (municipal council) and for the assembly of representatives of the 12 civic tribes of the city. It had a small cavea (seats set in a hemicycle) and a simple scenic wall with three monumental entrances. A section of the seating (cuneus) was reserved for the boule. The three remaining sections were allocated to representatives of each tribe in proportion to the importance of the tribe, as inscriptions carved on the seats attest. The theatre is the only place in the world found to date where such information on the local civic life of an ancient city is so well preserved.

It is unknown when the bouleuterion was constructed, but it may have been during the reign of Hadrian (117 - 138 AD), or perhaps even Trajan (reigned 98 - 117 AD). It was enlarged and transformed into an odeion in 165/166 AD with the addition of an upper level of seats. It was then equipped with a velum, a removable canvas covering suspended on cables.

The building was eventually abandoned and then reoccupied during the Umayyad era by potters before being reduced to ruins by the earthquake of 749 AD.
(From information on site)