I particularly appreciated this interview William Hill did with Dr. Bacon. It was kind of long but good. Especially when it discussed how the early Church would have understood the terms, psalms, hymns, and spiritual songs.
[video=vimeo;45884880]https://vimeo.com/45884880[/video]
[video=vimeo;45884880]https://vimeo.com/45884880[/video]