In recital, most pianists wander aimlessly through the centuries, beginning with the baroque and winding up with some Bartok. Not Emanuel Ax, who performed an evening of pieces in variation form Monday night at the University of Maryland Center of Adult Education.

Ax, in whose luxuriant sound one would be content to wallow, also gave listeners plenty to think about. ("Gave" is the right word, for Ax donated his services to University Community Concerts.) He began with some variations he commissioned -- from Andre Previn -- on a Haydn theme. Though the piece began with an interesting premise -- that variations are shifts in mood as well as theme -- the music veered off in the direction of showpiece: a splashy shower of notes here and there with no obvious connection to the theme. This is the stuff of which encores, not openers, are made.

In Beethoven's Op. 35, the variation tiptoes in as melodic ornament (in the bass) and sneaks out as melodic displacement. Sometimes, Ax's approach seemed too extroverted for passages that should be played, in the words of German musicologist Sigmund Lebert, "quite without shading, as if dreaming." A few other disappointments awaited audiences in the Webern Variations, Op. 27, rendered without the requisite dynamic and rhythmic shifting-on-a-dime. No complaints about the Schubert Impromptu in B-flat, D. 935 -- for this was an emotional and emotionally controlled reading.

Unlike Beethoven's and Schubert's variations, Liszt's Sonata in B Minor is based on more abstract thematic manipulation. Here, Ax swept away listeners into a glorious tapestry of sound.