Beethoven's Piano Concerto No. 5 in E-flat, Emperor, for solo piano and orchestra, has three movements (movements are large sections, alternately fast, slow, fast). A cadenza is a showy flourish played alone by the pianist. Before the 19th century, cadenzas were usually improvised on the spot.

Pianist Andre Watts took a few minutes recently to describe some interesting points for listeners about the concerto. He will perform it with the Cincinnati Symphony Orchestra Friday, Saturday and next Sunday:

"In this concerto you have this strange curtain raiser, with a big orchestral chord and a piano cadenza, and another chord, another piano cadenza, and a chord and a cadenza ... and finally the piece starts. It's very interesting.

"Also very meaningful is the fact that in all the previous concertos, there are places for cadenzas. Beethoven wrote some, but you could also improvise your own. But by the time he got to this concerto, he put words in the score (in Italian): 'play what is written here. Do not play your own cadenza.'

"It was clear he wanted to take more control. He didn't want a three- or four-minute interruption of his work.

"The slow movement is very beautiful. At the piano entrance, Beethoven says, 'twilight.' That's very meaningful (because) it gives you a sense of the color.

"The next unusual aspect is you have no break between the second and third movements. You actually hear the last movement's tune at the end of the second movement. And then it bursts out - as if, ah, that's what he meant.

"The last movement is a real, beer-barrel polka, kind of rompy. It has that often-caricatured Beethoven boisterousness and rough humor.

"One other thing for listeners is the unusual ending of the concerto, where there basically is a duet between timpani and piano. It's obviously something that he thought about. You half expect somebody to discover a piece for timpani and piano written by Beethoven."

Janelle Gelfand