I just received this information from the Musicians Union:

“Thankfully HMRC have now confirmed that a musician will be able to register just the digital part of their business for VAT so other work remains unaffected as long as total sales are below the VAT threshold.”

The full (but very short piece) http://www.musiciansunion.org.uk/news/2014/11/27/vat-place-of-supply-of-services-changes-due-in-2015/