Unable to list media items from razor template

Questions
1

I have media items including folders. I am able to list the contents of the media root using this code:

@foreach (var child in Umbraco.TypedMediaAtRoot()) {
<h5>@child.Url | @child.Name</h5>}

I can’t figure out how to start with a folder under the root. I don’t get any IntelliSense in VS2015, and I am having problems discovering the right solution.

This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/74570-unable-to-list-media-items-from-razor-template