Jeremy Denk's Joyfully Mad Ligeti : Deceptive Cadence Eavesdrop on the formidable pianist and blogger practicing a powerful etude in his Manhattan apartment.

Jeremy Denk's Joyfully Mad Ligeti

Armed with cameras and microphones, we recently invaded the rehearsal spaces of prominent musicians. The result is "In Practice," a new series of videos you can watch here.

In this clip, pianist Jeremy Denk is deep in György Ligeti land — thoroughly engrossed in the composer's solo piano etudes. Denk thinks of this music as "wonderful, joyful madness."

Book One of Ligeti's etudes closes with "Automne à Varsovie" (Autumn in Warsaw). Denk talks of the descending chromatic lines that make beautiful harmonies together but, he says, "the urge of the piece is toward an ever denser thicket of lines, an accumulation, crowding beauty out." At the etude's thrilling conclusion, the music flies boldly off the bottom of the keyboard.