"Sean's suggestion that anything that takes place in a folk club is folk is as valid as any other,"

This is not a suggestion, or a definition, it is simply an OBSERVATION based on what happens in the name of folk in Designated Folk Contexts. Only a very small minority of that would pass for folk according to a orthodox reading of the 1954 Definition, which is why I've suggested an expanded appreciation of it based on recent developments in Folkloric Research as detailed in Bob Trubshaw's Explore Folklore (Heart of Albion, 2003). Here Trubsaw demonstrates the mutability of the Folk concept especially in academic circles.

Personally, I feel it's all so much reactionary horseshit anyway and would sooner be living life than observing it, but the Folk Myth continues at some remove from the glorious realities of the situation. Thus Folk is a Faith, and the 1954 Definition is a Shibboleth of that faith, and what happens in the most Traditional of folk clubs has SFA to do with the glories of Traditional Song & Music however so persuasive the potency. Hell, I might be moved to tears by a Catholic Mass but it doesn't mean I'm about to start believing in God. I do believe in the human necessity of faith - but not the truth of it, far less the righteousness that that truth engenders.

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Which leaves the lady who walks into a folk club with her cello and plays Dvorak - where exactly? This serves perfectly to underline the nonsense of the 'anything goes' approach.

Not quite because the lady playing Dvorak on her cello in a folk club will only be there because there's nowhere else for her to play. I've heard her, and many like her; enthusiastic amateurs who come in fulfillment of the 1954 Definition by giving such otherwise composed music an idiosyncratic folk character in the the context of a community; and - well, empiricism is the key to all this and THERE'S NOTHING EVEN IN THE MOST ORTHODOX READING OF THE 1954 DEFINITION TO SAY DVORAK CAN'T BECOME FOLK MUSIC even in a revival context. The 1954 Definition is not about GENRE, it is about the Human Context of Music; it is about FOLK as an adjective, not a noun.

That said, ultimately I fear the 1954 Definition is utterly meaningless UNLESS you buy into the functionalist rhetoric in which it is couched and which justified the bourgeois plundering of traditional working-class culture in the first place. It is a relic, an anachronism, born from cultural patronage and the domination of a hierarchical social elite which saw fit to remove such treasures from their traditional cultural context and reinvent it elsewhere for fear of it dying out. For the vast majority of people it is dead anyway, but the culture from which it sprang is alive and well, just that it sings different songs now, and dances to different music. Otherwise, in the words of Kipling, I perceive no change - unlike others around here who pour their reactionary scorn on popular musical idioms that have a greater claim on being Traditional Musics than 90% of the dross that goes down in the name of Folk Music.

No language, just sound, that's all we need know,
To synchronise love to the beat of the show.
And we could dance!