I almost feel it is in the oncidium alliance somewhere now actual name dear heavens that is to broad a place to go. Im sorry but it is QUITE BEAUTIFUL! Good luck.
It looks like Odontoglossum cirrhosum to me or perhaps one of it's progeny; the lip is more intensely colored than photos that I have seen, but the form and markings of the flower look about correct.
Just my guess,
Adam
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I've never met an orchid I couldn't kill...