Hi Deb,
I've just set up from home, so may be able to help in some areas.
I contacted my local council to ensure I had all the appropriate insurance and certificates. A very good website for this is businesslink. You can put the details of your business start up and they will tell you which regulations/licences you may require. here is the web link for their getting started section
Business start-up organiser | Business Link
In relation to the use of your home for business purposes and how this will effect your council tax rates (which is what it will effect), you will need to contact your local valuations office who will assess the size of the area being used, if the area is solely used for business purposes, and the frequency of use for this purpose. They report back to your council, and to be honest, from what you've said so far, i don't think you'll be liable for business rates. You can get the details of your local valuations office from your local council. Just say to them that you need to know who to contact about having your house valued for business rates.
Other than that, house insurance can be affected, and any mortgage provider would need to be consulted first. You would normally find that your professional insurance will include public liability, but double check with them that it will cover your clients in this situation.
As sodabubble said, health and safety. A great website for help and guidance is HSE
Looking after occupational health safety and welfare in your business, and you can obtain a health and safety assessment pack from somewhere like Ellisons (that's where i got mine from) for the appropriate assessment forms, if required.
You will also need to obtain a music licence. see this thread
http://www.salongeek.com/biz-geek/63245-music-salons-license-needed.html for help on that.
i hope this helps, and feel free to pm me if you have any other q's.