Lucas Gonze wrote up an excellent description and analysis of the format I use for my Wrong Notes music podcast, which Lucas calls a Purple Podcast.

Lucas is using the word "purple" as a reference to the term, Purple Numbers, which is a technology or practice used by hypertext document creators. With Purple Numbers, creators mark-up each individual segment or fragment of a document in a manner that allows and encourages people to link directly to specific sections within the document. This provides more fine-grained alternatives to linking to only the whole document itself.

I create my podcast as a sequence of audio and music segments. Technology-wise, this naturally translates to a playlist, which is basically just a way to tell a music player: play this track first, this track second, this track third, etc.

But, since no major podcast player software recognizes playlists in podcasts, I publish my "podcast" in a manner that combines the requisite single mp3 podcast file with playlists that point to the individual audio segments. Each audio segment is posted as a separate mp3 file, and then is linkable via its own URL.

So, the "purple" outcome of all of this is that anyone can link to the individual segments in my podcasts, as well as linking to the podcast as a whole. And, this matches my intentions as the creator of the podcast—I imagine some people will listen to the whole "show," but others may listen only to a particular piece of music, or a particular segment of talking. I design my podcasts with these multiple modes of interactions in mind.

After I read Lucas' post (yesterday), I emailed him some comments and additional description about my approach. Lucas has posted these as well in Jay on Purple Podcasting. This describes in more detail how I produce my podcasts in my "purple" manner (which is a bit different than his purple manor, that I know you keep imagining!).