IT'S 25 years since Chick Corea - then a young member of the Miles Davis band - made an album called Now He Sings, Now He Sobs. As far as piano-trio jazz is concerned, it still sounds like the state of the art: pure, swinging and lyrical. Shortly afterwards, a solo piano album confirmed the impression of a musician with a fine touch and a terrific melodic imagination. To answer the question 'What went wrong, then?', choose one or more from the following: (a) Scientology, (b) electronics, (c) rock'n'roll envy, and / or (d) terrible taste in shirts / facial hair / drummers. Left alone with a grand piano, devoid of synthesisers and fellow L Ron Hubbard acolytes, he can still play wonderfully well (Leeds Town Hall, 0532 455505, tonight; RFH, SE1, 071-928 8800, tomorrow; Corn Exchange, Cambridge, 0223 357851, Tues; Royal, Nottingham, 0602 482525, Wed; Univ of Warwick, 0203 524524, Thurs).