To call William Byrd and John Bull "visionaries of piano music," as pianist Kit Armstrong does here, may be taking it a bit far, but it's not out of the question to perform English Renaissance keyboard music on the piano. Glenn Gould used to do so from time to time, and when the music of Byrd and especially Bull was first being unearthed, the piano was the default. It's likely, however, that the short pieces here have never received performances as detailed as these. Armstrong nicely differentiates the sober and classical Byrd from the wildly virtuosic Bull, whose music still has a distinctly experimental feel at a distance of four centuries. His execution of Bull's parallel runs is brilliant, and there's a delightfully fantasy-like quality to the variation sets. More generally, there's the kind of X factor here that comes from a performer's total commitment to and enthusiasm for a body of music, with all kinds of striking details. The album is beautifully recorded, and for all except those to whom Renaissance music on a piano is just a bridge too far, it will be quite a revelation.