WHY DO SO FEW people come to performances by the Harvard Concert Band? Thursday's concert-the band's sole concert this year-included works by Stravinsky and Copland and a world premiere, yet Sanders Theater seemed cavernous and bare because of the lack of the size of the crowd. Perhaps people expect only to hear Sousa marches and Harvard songs at a band concert. After all, that's what they hear at football games, where world premieres are rare indeed.

"Streams," (commissioned by Thomas Everett, the group's conductor) suggests that its composer David Cope has mellowed since the time he wrote "Yes," his most famous piece. Gone are the color slides and Moog tapes of that multi-media effort; added are eleven string players who contrast with the wind ensemble. Bypassing serialism in favor of a three-note motif, "Streams" emphasizes texture and unusual playing techniques. The required virtuoso percussion work came off well; the winds ruslted and the strings glid. The Cambridge fire house unwittingly added aleatoric effects, and a good time was had by all.

The band's playing reached its peak in the eclectic final work. Karel Husa's "Music for Prague 1968." Husa, winner of the 1969 Pulitzer Prize for Music, borrows whoel motifs from both Bartok and Holst, but draws most heavily on an old Czech song which Smetana, the fervently nationalistic 19th century Czech composer, dramatized in his massive Ma Vlast. Clear playing brought out the wide-ranging passions which inspired the work, both the mournful and the chauvinistic.

Though the Concert Band concerts usually stress the classic pieces for symphonic band, such as those by Hindemith and Schoenberg, this year's concert drew almost exclusively on recent works. In Aaron Copland's "Outdoor Overture," the earliest work performed, brass fanfare was emphasized to a point where all harmonic subtlety was lost, but in the surprisingly tonal ending of "Music for Prague 1968," the band showed strong ability to play in chorale fashion.

THE CONCERT BAND may be caught in a vicious cyle. It plays only one concert at Harvard each year, so there's not as much talk about it as there is about other Harvard music groups. Yet, at the present level of attendance, the band could hardly afford to put on more concerts and thus gain wider publicity. The group can play well enough to effectively help promote both music for symphonic band and modern music in general. It's very sad it's not better known.