Pennsylvania native Samuel Barber (1910-1981) was noted for the lyricism and romanticism of his music, and is regarded as one of the great American composers of the 20th century.  A child prodigy who trained at the Curtis Institute as a teenager, he went on to win numerous awards for his compositions including the Prix de Rome, two Pulitzer Prizes, a Guggenheim Fellowship, and membership to the American Academy of Arts and Letters.  He is best known for his Adagio for Strings, his soprano and orchestra piece Knoxville: Summer of 1915, and many other orchestral and operatic works.  He met the Italian-American composer Gian Carlo Menotti during his Curtis days, and the two forged a life-long professional and personal partnership, living together in Mt. Kisco, New York for several decades.

Commando March was written in 1943.  It was World War II, and emerging composer Barber was in the military (drafted in 1942) and attached to the Army Air Forces.  Commando March was a product of this time in the military, and remains his only widely-played band piece (there was also a less successful Funeral March from the same time period).  Here it is in a recording by the “President’s Own” United States Marine Band:

Read more about Barber at Wikipedia and Music Sales Classical.  Commando March is featured at the U.S. Air Force Band and Hal Leonard (in Dr. Andy Collinsworth’s indispensable full-score critical edition).