A few days ago the National Symphony Orchestra turned the Capitol grounds into a glorious concert hall. Last night it turned the Kennedy Center Concert Hall into a park band shell, with light music from Offenbach to Sondheim and quite a lot of fun.

Still, this "pops" concert also had substance, in Mozart's Piano Concerto No. 21 in C Major. The solist was Ana Maria Vera, a 16-year-old of angelic presence and heavenly promise. One expects a bit more passion in this piece, particularly in the sublime middle movement; but quibbles over little legato or cold technique are banished in the face of such cascades of lovely notes, played with freshness as well as accuracy. Whatever else you may have planned for this evening, drop it and go hear Vera tonight when the NSO repeats the concert.

The orchestra was in fine technical estate, even when lacking the superhuman command felt on Monday night. Erich Kunzel is no Shostakovich, but he is a lively leader. If the rushed outer movements of the Mozart bordered on vulgar, he allowed a hint of portamento in the strings during the andante that was a refreshing surprise. And in selections from the 1937 ballet "Gaite Parisienne," the pulse of high kicks and wine was palpable in the hall.