On a blistering hot afternoon in July, pianist, Siqian Li, delivered a spectacular performance of romantic repertoire at St James’s Church, Piccadilly. Chopin’s Sonata No.2, comprising the famous Funeral March, and a new arrangement of Ravel’s Valse, topped the virtuosic bill. Li drew quite a crowd*, even in the heat.  Karine Hetherington of ArtMuseLondon went…