SOME years ago a partnership known as Norah Blaney and Gwen Farrar was dissolved. It was like the splitting of a star, and where there had been one light in the theatrical firmament there now twinkled two, one of whom will come to the microphone for a quarter of an hour tonight. Norah Blaney is a pianist and a composer as well as an actress and singer, although it was in the last capacities that she played so charmingly in The Vagabond King, and since then she has been playing a straight part in Out of the Blue. But with all these talents she is obviously capable of putting up a really first-rate one-man show' when she visits the Studio tonight.