By the time the Orchestre de Paris and its chorus finished singing "The Star Spangled Banner" last night, to open their share of the Paris Festival now going full blast in the Kennedy Center, a mild electric shock had gone through many in the audience.

And by the time they finished "La Marseillise," there were many in the Concert Hall who, at least for the moment, did not care whether or not they heard another note all evening. First of all, those 160 young French singers - the chorus is not five years into history and its average age looks to be around 30 - poured out our national anthem in clear English with a sound that has rarely been heard in that song.

But "La Marseillaise"! It came in the Berlioz arrangement, though not all seven or eight verses. But there were the startling key changes, the stunning unison octaves, and twice those electrifying phrases that reach up to the top B flat. If a tidal wave of American-French emotion was needed to launch this festival, conductor Daniel Barenboim, his orchestra and his singers provided it in spades! Both anthems should be required at the beginning of every concert by these two great ensembles.

Berlioz did follow Berlioz, however, as Barebolm led a supercharged performance of the "Damnation of Faust." Full of nuances in tempo and dynamics, his reading created dramatic tension, making the most of every opportunity to underline Berlioz' genius.

Throughout the long work, the chorus was the element that continued to astound. Its responses is instantaneous, its coloration of the text brilliant as few choruses even begin to suggest. Soft choral sibilants splashed vividly with or against soloists and orchestra, and in the large passages, there was a torrent, thoroughly disciplined, but overwhelming, to fulfill the composer's fondest dreams.

Jules Bastin was the Mephistopheles, by turns, sardonic and menacing or, with sneering, biting tones, snaring his victim, Faust. In his slightest movement, he was the ultimate embodiment of evil cynicism.

Stuart Burrows sang Faust with ease, showing off a mezza voce of lovely quality, and in all but the highest reaches of the role handling its heavy demands without strain.

Jessye Norman was the Marguerite, a part of which her voice and temperament are ideal, for it asks real substance in the lower range, which Norman supplies effortlessly. Her feeling for the language is also a strong asset.

Pali Marinov was a useful Brander, and, at the close, Annemarie Beck sang the celestial voice.

The splendor of the evening, however, came most often from Barenboim and the fiery orchestra and chorus. The latter, in the closing pages, where Berlioz throws in the demonic language he invented for the demons to sing ("Tradioun marexil fir tru dinxe burrudixe") was only a final proof of the greatness of the chorus. It is really a shame Berlioz did not close with that scene.

Tonight: Tristia, with chorus, and the Fantastic Symphony. CAPTION: Picture 1, Daniel Barenboim conducting L'Orchestre de Paris; Picture 2, Genevieve Casile and Frncois Beaulieu; by Agence de Presse Bernand