BIMM (the British and Irish Modern Music Institute) said that it wanted to teach students on the ground floor of the Portslade building, known as the Circle.
The three-storey building, between North Street, Camden Street and Wellington Road, is on the old Flexer Sacks factory site.
Most recently, the building, owned by developer Farshad Ghiaci has been used as a gym and arts centre.
Brighton and Hove City Council granted planning permission for a change to educational use – and for BIMM to knock the three smallest dance studios together to create a larger space.
The college said that it wanted to turn a large storage area into smaller vocal studios and rehearsal rooms while retaining an existing auditorium.
BIMM added that the site would also be used by its partner college, the Institute for Contemporary Theatre.
The council gave BIMM three years to start work on the internal changes and said that cycle parking must be in place before the building could open to students.
Once the music school moves in, it will have three months to submit a travel plan to the council.