Pianist Albert Zak, a virtuoso performer who began to play the piano at age 4 and was, at the time, the youngest person taking classes in Toronto's Royal Conservatory of Music, appears at 7:30 tonight at Reinberger Chamber Hall at Severance Hall for a solo recital that includes works by Chopin, Rachmaninoff and Debussy. Tickets are $20 to $50. (Niesel)