Tonight is one of those rare occasions when the Opera House will open its doors. The event is the introduction of the Jooss European Ballet to Boston in a group of three original numbers, the most significant and interesting of which is "The Green Table", a parody on the League of Nations type of conference. It was awarded first prize in the last International Competition at Paris and has attracted considerable attention both here and abroad.

Hill's String Quartet

The second concert in the Chardon String Quartet's series takes place at Paine Hall tomorrow night, and is distinguished by the fact that Professor Hill's First String Quartet is to receive its initial performance. Professor Hill has during the past dozen years ventured far and wide in the field of composition, and many of his works including his first two symphonies and his orchestral poem "Lilacs" have been played by Dr. Koussevitsky and the Boston Symphony Orchestra. His new contribution to quartet literature is awaited with great interest.

Athens Conservatory Leader

A newcomer to America, Dmitri Mitropoulos, leader of the Athens Conservatory, comes as conductor to the Boston Symphony during the next two weeks. His program for Friday and Saturday as well as Monday evening consists of Beethoven's "Overture to Leonore No. 2," "Overture for a Don Quixote" by Jean Rivier, Debussy's three symphonic sketches "La Mer", and Strauss's "Symphonia Domestica". Rivier is a modern French composer whose works have received considerable although not unusual praise in Paris during the past eight or ten years. His "Overture for a Don Quixote" is one of his latest endeavors.

Danish Soprano at Jordan

Two very fine artists are also to be heard this week. Tomorrow evening in Jordan Hall, Povla Frijsh, famous Danish soprano, is giving a long and varied program which bids fair to be something quite out of the ordinary and well worth hearing. Songs by Schubert, Grieg, Moussorgsky, Debussy, Sibelius, and Ravel are included in the imposing list which gives one every reason to believe that the superlatives which she earned in her New York reviews were more than justified. The other artist is Mischa Elman, noted violinist.