London's teacher of the Bolshoi tradition

In a London dance studio, far away from her homeland, a pleasant, diminutive woman dressed in black sweater and black pedal-pusher pants holds a vital key to unlocking details of Bolshoi Ballet tradition.

Her name: Sulamith Mikhailovna Messerer, a member of the most famous family in Soviet ballet today and herself a decorated dancer and now teacher.

Her dancer-choreographer brother, Asaf Messerer, at 80, continues to teach the daily exercise class for the Bolshoi Company in Moscow. Her nephew Boris is a set designer for ballets. Her niece, longtime prima ballerina Maya Plisetskaya , is still dancing and choreographing.

Mme. Messerer brought her own unrivaled knowledge to the West in February 1980 when she and her son Mikhail defected. She was working as a guest teacher with the Tokyo Ballet Company. Mikhail, a dancer, had come with the Bolshoi Company on tour to Japan.

Living in Moscow at the time of the defection, I remember telling Bolshoi friends the hot-off-the-wire news, the kind that would never be announced in the Soviet press. Coming only six months after the first-ever Bolshoi defections of Alexander Godunov and Leonid and Valentina Kozlov, it was a genuine ''Bolshoi Skandal.''

Soon thereafter, morale in the company fell to an all-time low and rumors were rife. My friends were astounded. Here was someone whose name was synonymous with Soviet ballet, an honored and therefore privileged member of Russian society.

Mme. Messerer has said that she defected to allow her son more freedom to dance and to travel. It is speculated that the real reason was Bolshoi politics, and her own disagreements with Yuri Grigorovich, chief choreographer and artistic director.

She had had the permission and approval of the Culture Ministry itself to teach overseas in Sri Lanka and Japan, where she was a regular visitor for 13 years and learned the language fluently.

She went her way via the United States to England. ''Baryshnikov and Lucia Chase (of the American Ballet Theater) didn't want me'' - she shrugged her shoulders - ''and I got invitation to teach Royal Ballet for one month,'' she told me.

That was almost three years ago. Now settled in London, she responded speedily to my own attempt at a Japanese introduction learned many years ago. With fluency and humor she left me far behind.

Quickly we switched to a mixture of Russian and English. ''I like it here,'' she said. ''The workers are very disciplined and organized.''

She teaches classes daily (''I never take holidays''), running from the Royal Ballet Company in Covent Garden to the Royal Ballet Upper School in Hammersmith to open classes at Dance Works, off Oxford Street, where for (STR)2.50 ($3.65) any budding dancer can take her advanced class on weekdays. Future Nureyevs and Makarovas can take weekend ''babies'' classes.

She has also opened her own school, which, she admitted, has had financial problems. But she hopes to persevere and eventually to produce dancers for her own company.

''This summer I went to Japan for one month. No, not for holiday but to teach. So many friends came . . . .'' She smiled, remembering.

Sulamith Messerer has pedigree qualifications for her work.

Graduating from the Bolshoi School in 1926, she danced with the company for almost 25 years. Her most famous roles were Jeanne from ''The Flames of Paris,'' Tao-Hoa from ''The Red Poppy,'' Nikia from ''La Bayadere,'' and Zarema from ''The Fountain of Bakhchisarai.''

Often she partnered her brother Asaf. With him in 1933 she was the first Soviet ballerina to travel abroad after the 1917 revolution.

Natalia Roslavleva, the noted Soviet dance writer, describes her in her book ''Era of the Russia Ballet 1770-1965'' (published in London in 1966, well before the defection) as ''a brilliant virtuosity ballerina.''

When a young dance student, she also became the women's sprint champion swimmer of the Soviet Union, and had to choose which of the careers she was going to pursue.

She was honored with a gold medal of the Order of Lenin, made a People's Artist of the USSR (the highest such medal awarded), and a State Prize Laureate.

Yet today, like other defectors before her, her name has been erased or excluded from books and articles, including the Soviet Ballet Encyclopedia printed in the summer of 1980. (The space that obviously must have been allotted to her was filled with a very long description of her nephew Boris.)

Like Nureyev, Makarova, the Panovs, Baryshnikov, and Godunov who defected before her, Sulamith and Mikhail Messerer have officially never existed in Soviet ballet history.

What is it that the West can learn from her? Why is she such a rarity?

First, her knowledge of Soviet ballet is unique. It spans more than half a century, longer than any of the other defectors' entire lives. Her teacher during her career was Elizaveta Gerdt, whose own father, Pavel, was the famous danseur noble of the Imperial Russian Ballet in St. Petersburg and for whom Petipa created many of his princely roles.

Mme. Messerer has memorized the choreography of ballets and technical sequences never seen in the West - ''I always learned the steps quickly as a girl.'' Now she is imparting her years of experience from the best classical training in the world.

On top of this is her strong Russian character, which pushes her past normal limitations (and often produces criticism and jealousies).

The treasures she is handing down to new generations were briefly glimpsed at a star-studded gala held recently (Nov. 13) to celebrate her 75th birthday (just three days earlier than another gala held at the Bolshoi in Moscow to mark Asaf's 80th birthday).

It was an evening filled with nostalgia for Sulamith Messerer (dressed not in her usual black but in pale apricot chiffon), for most of the selected extracts were ones that had made her famous.

Music by such composers as Gluck, Khatchaturian, Rachmaninoff . . . choreography by Gorsky, Vaganova, Goleizovsky, Vainonen, and Asaf Messerer filled the bill.

Soloists from the Tokyo Ballet sparkled with confidence and enthusiasm in two quaintly old-fashioned extracts, ''Frescoes'' and ''Ocean and Pearls,'' from the ''Humped-back Horse.''

Some of the British stars such as Briony Brind as Nikia in ''La Bayadere'' and Monica Mason as the gypsy in ''Don Quixote'' had difficulty with characterization and feeling in their solos, which had been taken out of context and therefore lacked the anticipation and mood a full ballet offers. These stars were challenged to demonstrate that vital Soviet ingredient - flamboyancy.

Others such as Wayne Eagling reveled in it, and he was met with thunderous applause after his ''Flames of Paris'' duet with Karen Paisley.

Saint-Saens' ''Dying Swan,'' a piece that Messerer prepared with her niece Maya Plisetskaya 45 years ago, when Maya was 13, and which Plisetskaya still brilliantly performs, was given a gentle, fluttering rendition by Pippa Wylde.

The packed-to-overflowing London coliseum showed its appreciation of Russia's dancer-teacher and her impressive knowledge.

British reviews were mixed. They concentrated on the dancers rather than on the choreography, which was the reason for the evening.

Next morning, at 10:30, Sulamith Messerer was back at work, teaching a class.