Why does this musician/entertainer's website seem to be partly a business website?
Any serious musician/entertainer is a businessperson: They want to make a living selling their products; so they are a business.
It's a heck of a lot easier to set up a business online at first, even if it becomes a more physical than online business eventually. That applies to musicians too - So as a musician it's good to have an online business - even if it's only a part of the whole business setup - based around a blog / website.
Why does this musician/entertainer's website seem to be partly a technology website?
Any serious musician/entertainer needs technical assistance or likes to add to their technical know-how: They want to make a living with what they earn; not spend it all on paid professional technical help. The more technical stuff a musician/entertainer knows the better it will be for them.