Candidates for each of the elective officers to be voted for at any municipal election under the provisions of this Charter shall be nominated at a nonpartisan primary election to be held on the sixth (6th) Tuesday before the regular municipal election. 
   Any matter which, by the terms of this Charter, may be submitted to the electors of the City at any special election, may be submitted at either the general municipal election or at the primary election, as provided for herein.