Split rail function generator or single rail ?

[lordvader88]

I want to make a project to use a little split rail linear PSU I should have made already. So I'd like to make some BJT and/or op-amp function gen. like they might have in the 1960/70s with RC and LC circuits for audio frequency and AM band (if I can find a 'real' schematic') and solder it up today for fun.

Do professional/$$$ function generators usually output +V/-V or is it 0-->V+ ? I have a XR2206 function gen. kit that's single rail, so I should built a split rail type I guess.