To search Youtube, you tap the small search icon in the top-right.
You can then start typing, or tap the audio icon on the right of the search field to voice search.
Here we go with the typing option.
We get all search results initially, but we can switch between tabs to get results for just channels and playlists.
We now try the audio search option and it seems to work fairly well.
We can and sort our search results and filter them by date, duration, and "features."