Hey Charlotte...
Re. your post a few back - "what is it that makes them so different apart from the cello"...

This is what I think on the subject:

1) Harmony. This is the main reason I like them. I like simple harmony I prefer chords with extensions and coloured alterations. I think they have a good balance between the two with some progressions and voicings that are out of the ordinary. Belinda's sense of harmony and Adrian, Becky, Niopha and Rachel's taste in soundworlds seems to have led them to choose very beautiful, unconventional chord progressions. Instead of the usual tried and tested tonic-dominant polarity they use nice progressions like major 7th chords resolving up a major third, which sounds beautiful and unsettling. They use sharp 11ths and augmented triads and I love the sound of that harmony. It's Bill Evans-ish. It is pretty 'different' in folk I think. A really sophisticated sense of harmony is one of the reasons I like Joni Mitchell so much. Their vocal harmonies can be very close and sound a bit different, with tone/semitone clashes, tritones and accented suspended dissonances. It sounds really interesting. They use lots of different modes but I like that they don't mix them up to much - their songs seem to stick to one mode with very noticeable peak points when they add a chromatic note and it's really nice. Like they're retaining the beautiful simplicity of folk, but translating it into the unusual soundworld of contemporary jazz.
2) The way they use piano couldn't possibly be further from silly Cecil Sharp drawing room. It's innovative. Drones on piano are a bold thing to do. Using it as a bell-like sound. Holding the sustain pedal for a ridiculously long time is just not the done thing but it works. Playing high up in the piano register while the singers sing lines beneath. That's quite quirky. Then all the Tin pan alley pastiche. It's not the commonest thing in folk is it?
3) Feet in very high heels as percussion. Enough said.
4) I think Becky and Rachel's voices are unique and powerfully honest and communicative. But this is a particularly subjective point I realise.

I don't really see what's so different about the cello...

S