My understanding of Wendy filters (as originally described) is that it's just a logical "NOT" of a playlist.

The Wendy filters are much more flexible than that. Now I realize I have to shut up because I shouldn't give anything away. Suffice it to say that what you're talking about is the sort of thing Wendy filters can do. I'm not sure if you'd be able to do as much as you wanted "on the fly", though.

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Tony Fabris
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Tony Fabris