The London Symphony, in town for two Kennedy Center concerts, played the first of them last night for an audience that came close to filling the Concert Hall.

Conductor Claudio Abbado has an enthusiastic following in town, due undoubtedly to his previous orchestral appearances as well as his direction of La Scala several seasons back. The London Symphony, of which he is principal conductor, is one of Europe's best, though there were times last night when it was not in top form. The Berlioz Roman Carnival Overture began the program solidly enough, though with little of the barn-burning excitement that recent National Symphony audiences have heard in the same music.

There was little lacking, however, in Abbado's reading of the suite from Bartok's "Miraculous Mandarin." With the unusual luxury of the organ that is called for very briefly, the orchestra unleashed great but well-controlled power and some exquisitely sensuous playing. Special praise goes to the first clarinet for the fluent, rapturous phrasing of his crucial solos. Abbado led the music with a tight rein in the wild pages but took the full measure of expressive liberty in the seductive spots.

The Fourth Symphony of Tchaikovsky closed the evening with the largest inconsistencies. The horns were in and out of trouble from the opening notes, and there were problems in articulation in the top woodwinds in some of the fiery measures, though most of the time the same choir was in fine shape. The pizzicato movement was a pleasure, with the winds and strings perfect synchronization. But much of the time, especially in the first two movements, Abbado led the music in a way that unduly emphasized its episodic character. An underlying pulse which it needs was missing.