Piano recitals by John Roberts are infrequent but they are events usually worth waiting for. His programs are enterprising; they frequently include works well off the beaten track like the compilation offered at the Conservatorium of Music on Sunday. It featured rare airings (for Perth) of sonatas by Samuel Barber and Argentinian composer Alberto Ginastera. The latter is a vast, taxing and intricate work and it was a good vehicle for Roberts to demonstrate his skill in giving point and meaning to music which in other than assured hands, can sound formless, meandering, mystifying or dull. Roberts succeeded throughout in expounding the sonata’s musical argument in a lucid and cogent way. He communicates. The rapid, eerie whisperings of the second movement, for instance – intriguingly reminiscent of the ghostly conclusion to Chopin’s Funeral March Sonata – were conveyed in a most effective sense. For those whose acquaintance with American Composer Samuel Barber is limited to occasional exposure to his Adagio for Strings, his piano sonata is likely to be a startling experience. Its fourth movement is a terrifyingly difficult fugue, as daunting to play in its way as the conclusion of Franck’s Prelude, Chorale and Fugue or the finger -cracking finale of Brahms’ Variations on a Theme by Handel. It comes as no surprise to learn that Barber wrote his sonata with Horowitz in mind. This is not music for the tentative, tinkle-fingered pianist and it is pleasing to report that Roberts gave a remarkably energetic and coherent demonstration of contrapuntal keyboard playing here, hurling great bolts of sound into the auditorium like some pianistic Zeus.