László Fassang is definitely not your run-of-the-mill stodgy organist. The handsome young Budapest-born keyboard whiz has a mischievous, confident smile that warns you to fasten your seatbelt cause hes about to make those pipes roar like youve never heard them. Critics have lauded Fassangs performance of Bachs treacherous D major Prelude and Fugue as a true marvel, and his mastery of another treacherous composer, Franz Liszt, is capable of taking the breath away. Fassang grabs prizes right and left; he took the Grand Prix de Chartres and the Audience Prize at the 2004 Chartres International Organ Competition, the 2002 Improvisation Gold Medal at the Royal Bank Calgary International Organ Festival and Competition, and a couple of top honors at the Fourth International Organ Competition of the City of Paris without any trouble. This week he comes to the Music Center with a daunting program that includes Bachs Toccata, Adagio and Fugue in C major and Chaconne from the D minor Partita; Brahms Five Chorale Preludes; Liszts Prelude and Fugue on B-A-C-H; and the showstopper of showstoppers: his own arrangement of four Hungarian Dances by Brahms. Plus, for some fun, hell do an on-the-spot improvisation of a given theme with, no doubt, some jazz/folk frills. Walt Disney Concert Hall; Sun., Feb. 11, 7:30 p.m.; $21-$45. (323) 850-2000 or www.laphil.com.