Eugene Ormandy, appearing this week as guest conductor of the National Symphony, persuaded the orchestra last night to some of the finest playing it has ever given its audiences.

All three of the works on the program were played grandly, marked with a particular feeling for style. Each of the three was written in this century, though Debussy's "La Mer" and the Second Symphony of Sibelius came soon after the century began. Roy Harris's Third Symphony profited from Ormandy's overview of its long line, a design in no way altered by the composer's ingenious changes of mood during the course of the one-movement structure.

Ormandy brought to it the vibrant vitality which is its essence. While each section of the orchestra seemed to take on a special glow during the concert, the strings in particular, with many opportunities to shine, played with unusual luster throughout. Their excellence was matched by the brass for whom Harris wrote gusty entrances that came off ideally.

The evening's most alluring magic came in the Debussy. Ormandy and the players achieved the widest possible dynamic range, clothing the music in sounds of sensuous beauty. The moment when the English horn and cello mingled their voices was of a rapture rarely encountered.

As he knew Roy Harris personally, so Ormandy also was a friend of Sibelius. In the symphony he opened vistas of lyric poetry and grandeur that are often missed. It was a reading filled with superb playing under a master conductor. The orchestra, honoring its distinguished visitor, at times refused to stand to join him in acknowledging the applause.