Couldn't get Taglib to work
This is because you downloaded TagLib Sharp build and C# Source code and not the compiled binaries (the DLL). Can be found there http://download.banshee.fm/taglib-sharp/
Open the archive, find the DLL and place them wherever you want and point to them in [Reflection.Assembly]::LoadFrom
You can also install the tagLib Sharp Library via Nuget package manager
The latest compiled binaries as far as I know is 126.96.36.199. the "master" is essentially the same. If a newer version is available I don't think it was ported to a DLL from the original TagLib Sharp project owners. You'll have to compile and build yourself.