If Scotland become an independent country they would take part in the Eurovision Song Contest. The 670 page “white paper” answers a number of questions about Scottish Independence. The future of the Scottish Broadcasting Service is one of the key questions, in the “white paper” it says that:
The SBS would seek membership of the EBU and would be an active and constructive partner in the organisation. As part of this participation, we would envisage the SBS engaging with some of the EBU competitions, including Scottish entries in the Eurovision Song Contest.
So if Scotland votes for independence, Scotland becomes independent in 2016 and would be able to participate in Eurovision from 2017 at the earliest.