With more than 6000 persons attending, the University Band will give one of the most important concerts of the year this afternoon from 4 to 6 o'clock in the quadrangle of the Medical School at the annual convention of the American Medical Association. The entire personnel of the band, 48 pieces, will take part. Saturday the band will again play before the Association at Plymouth. Today's program, which consists of twelve selections, is as follows: 1. March, Front Section,  Bagley 2. Overture, Raymond,  Thomas 3. Suite  Grieg a. Morning b. Ase's Death From "Peer Gynt" 4. Selection, The Bohemian Girl,  Balfe 5. March, Harvard University Band  L. J. Abbott '24 6. Three Popular Songs: a Wang-Wang Blues b. Mello-Cello c. Margie Intermission 7. Overture, Light Cavalry,  Suppe 8. March, Colonel Miner, Rosenkrans 9. Selection from "Hansel and Gretel"  Humperdinck 10. Harvard Songs: Harvardiana Soldiers Field Our Director 11. Selection, Maytime.  Romberg 12. March, Dunlap Commandery,  Hall