This is a red-letter week for the Vagabond. The season's first appearance in Cambridge of Serge Koussevitzky and the Boston Symphony Orchestra is sufficient to evoke enthusiasm from The Vagabond, who has not forgotten the first of the series of concerts which have periodically relieved the strain of a pedestrian education. Thursday's program from Beethoven. Stravinsky, and Tchaikowsky holds a pleasant promise to carry over the last stretch of hour examinations.

But there is music in the air before Thursday. This evening the Stradivarius Quartet of New York City will give as the first of their three programs. "Quartet in F major" from Mozart, and Schumann's "Quartet in F Major, Op. 41, No. 2". Four Stradivarius instruments will be used in the concert.

Also not to be missed are the lectures by four visiting professors: President Henri Guy of the University of Grenoble, Professor H. W. Garrod of Oxford, Professor Wolfgang Liepe of the University of Kiel, and Professor Marcel Aubert of the Ecole des Chartes, Paris. The special lectures follow:

TODAY

"Das Theater in Deutschland" I "Das Mittelalter." (illustrated). Professor Liepe, four thirty o'clock in Old Fogg Lecture Room.

Stradivarius Quartet, Court of Fogg Art Museum, eight o'clock.

TOMORROW

"La Vie et les Oeuvres de Jean Racine" IX, President Guy, five o'clock, Emerson D.

NOVEMBER 6

"Matthew Arnold", Professor Garrod, eight o'clock, Fogg Art Museum.

NOVEMBER 7

"La Cathedrale d'Amiens", Professor Aubert, four thirty o'clock. Fogg Art Museum.

Boston Symphony Orchestra Concert, Sandors Theater, eight o'clock.

NOVEMBER 8

"La Vie et les Oeuvres de Jean Racine" X. President Guy, five o'clock, Emerson P.