On a warm, sunny afternoon in this small suburb of Cleveland, I listened recently in astonishment to a live performance of the third orchestral suite by Johann Sebastian Bach. The ornaments were being played correctly - as easily and naturally as if the members of the student orchestra were all named Bach. It was the first time in my life I had ever heard this familiar music played with the right embellishments, except on a very few recordings.

But since Berea has been the home of a Bach Festival every year since 1933, I should not have been so surprised. Bach's 300th birthday is six years away, but Berea has been getting ready for it for 47 years.

It all began in 1898 when a young musician named Albert Riemenschneider started a conservatory in Berea, where he was born 20 years earlier. An organist and conductor, Riemenschneider was determined from the very beginning of the new conservatory, which he called Baldwin-Wallace, to have a Bach Festival there every year. The most famous American Bach Festival is the one in Bethlehem, Pa., begun in 1900 by J. Fred Wolle. Both Wolle and Riemenschneider were organists passionately determined to make the great works of Bach well known in this country. Having given the first performances in the United States of both the St. Matthew and the St. John Passions, Wolle in 1900 gave the first complete American performance of the B Minor Mass.

Riemenschneider vowed that what could be done in Bethlehem could be done in Berea and in 1933, at the depth of the Great Depression, he began a Bach Festival which has continued every year since that time. Today it offers performances of high standards with singers and players from both the resident faculty and students of the conservatory and the concert world of this country and Europe.

In this year's festival, the guest flute soloist was Paula Robison, whose playing is known in the Kennedy and Lincoln Centers of Washington and New York for its flawless style and for the kind of zest and brilliance Robison adds to any performance. In the familiar Telemann Suite for flute and strings, with the expert conducting of the festival's music director, Dwight Oltman, Robison turned in a dazzling account.

But her playing was hardly more astounding than the stylish fire of the orchestra's first trumpet, a somewhat grandmotherly-looking woman named Mary Squire, who sat at the back of the chamber ensemble and delivered some of the finest Bach trumpet playing to be heard anywhere.

That's the kind of thing Riemenschneider envisioned when he opened his first Bach Festival 27 years ago. His insistence upon the highest standards has been upheld in the intervening years. In that time, the Berea festivals have presented the greater choral works on a rotating basis, rolling up totals of 13 B Minor Masses, 12 Magnificats, 10 performances each of the St. John Passion and the Christmas Oratorio, and nine St. Matthews. Seventy five of the cantatas have been sung in over 120 performances; all of the motets, the orchestral suites and Brandenburg concertos have been heard, as well as the Musical Offering, and a wide range of the chamber works such as the violin-keyboard sonatas, the flute sonatas and solo keyboard works.

While Johann Sebastian Bach has always been the central attraction of the Berea Festivals, his music has, from time to time, been performed in conjunction with works by other baroque masters from Monteverdi to Handel and Buxtehude.The only post-Bach composers to be included in the festivals, in addition to Sebastian's sons, have been Mozart and, in a rare departure, Stravinsky, with his Dumbarton Oaks Concerto.

The Berea concerts are given in the superb hall of the Kulas Musical Arts Building. Its moderate size and excellent acoustics, the result of a renovation within the shell of a venerable stone building, make it ideal for the festival which attracts audiences from the greater Cleveland area.

Some Washington music lovers with good memories for concerts at the Phillips Collection will remember an outstanding violin recital played there some years ago by George Poinar. The program included sonatas by Enesco and Bartok and was played on the highest artistic level. Poinar's visit to Washington was a glimpse of the performance standards that were regular occurrences at the Berea festivals - of which he was for some years the director.

Avoiding any suggestion of the parochial, the guest conductor of the festival several years ago was Helmut Rilling of Stuttgart, Germany, who annually conducts Bach festivals throughout the world, and who is at present involved in recording all the known Bach cantatas by the year 1985, the 300th anniversary of Bach's birth.

The new music director of the Berea festivals is Dwight Oltman, whose conducting of Bach and Telemann might make you think he is a baroque specialist until you learn that in addition to directing the Ohio Chamber Orchestra for the past seven years, he is also music director of the Cleveland Ballet. His leadership added style to the dance movements of the Telemann suite, brilliance to that third suite overheard in rehearsal, and unmistakable authority to the performances of this year's Bach.

In Berea these days, they are looking not at one but two anniversary years: 1982, when they will hold their 50th Bach Festival, and 1985, when they, along with the entire musical world, will mark the 300th anniversary of the birth of Sebastian Bach.

Baldwin-Wallace hopes by 1982 to be able to give its 50th festival not only in Berea but also in either Chicago, New York, or Washington. And so it should. It is too good to be confined to the Berea area. Its stature makes it well worth hearing in the Kennedy Center's Terrace Theater. No other ensemble yet heard in the Center has played Bach orchestral music as correctly and with the same kind of style asthese Berea Bachers.