The sites created by MyBandSite.ca run on an extremely powerful "content management system", and that system is designed to put control of the content (the "what" of your web site) into the hands of those that might not be able to handle "how" that content is put on the page. Let MyBandSite.ca worry about the layout, colours, fonts, yadda yadda. You concentrate on making your site current by posting news, reviews, blog entries...you name it...as often as you are comfortable with it.
And it is easy. Honestly. You simply log into your site (it is password protected to prevent your site from being spammed), and edit any existing content that MyBandSite.ca has created for you, or add new content as you see fit.