For some keyboard players, Bach's great Goldberg Variations are an altar at which they pay homage, reverentially bowed, even cowed. Not so pianist Joanna MacGregor. Her instinct is to celebrate and demystify.

And as if her reputation didn't guarantee a coolly irreverent approach, her programme notes for this recital at St George's marked some variations with the equivalent of Day-Glo highlighter. Number 11 became the Betty Boop variation, by association with a T-shirt shop passed daily in Sydney when MacGregor was learning the work, and Variation 17 is laughing gas.

MacGregor's ultimate concern, though, seemed here to be for the humanity of Bach, who may have created a work of consummate technical artistry, but whose compassion emerges through the most complex of musical webs. So it was in the slow variations that MacGregor was at her most eloquent. Her handling of the colossal structure was also astute, with the cumulative effect of the rising canons and rising emotional temperature achieving a blistering heat towards the end of the cycle.

For purists who prefer harpsichord thinking to provide the context for the Goldbergs, MacGregor's use of the sustaining pedal will have been excessive. Yet, if the evidence of Bach's excitement at improvising on JG Silbermann's new fortepianos towards the end of his life is put into the equation, it offers licence to experiment. And, anyway, MacGregor needs no bidding on that score. The swirling mist of sound she made of the end of the penultimate quodlibet was almost shocking, but out of this emerged the original aria theme, breaking through the aural horizon, at first tentatively and then gently but majestically. It was an inspired touch.