THE MARINE ATTITUDE toward music was stated succinctly some years ago, at a time when most of the military bands that grace this city were into diversification: singers, bluegrass groups, jazz combos, strolling strings. "Those others," scoffed a leader of the Marine Band, "with their 'wind ensembles' and choruses -- we've got a goddamned band, B-A-N-D, band."

There's something to be said for the idea that military bands ought to stick with what they've always done best, which is to march down the avenue and play rousing music, and leave to others the sensitive rendering of Beethoven's later string quartets. That's why there was shock and dismay recently when the Marines declined to march in the rain.

A Marine band from Parris Island, S.C., was to participate in a constitutional bicentennial parade in Leominster, Mass., Sept. 20. But according to the parade chairman, Victor W. Leger, when parade day came it was raining, and he was told that "Marines do not march in parades if it's raining prior to the start of the parade; we do not want to get our instruments wet; and we did not take our raincoats with us."

At this point in the story, we envision the Boy Scouts' contingent marching smugly along Leominster's main street wearing slickers and carrying a banner that reads "Be Prepared," while 76 long-dead trombonists and John Philip Sousa turn over in their graves. Oh where, they might have been asking, are the Marine bandsmen who carried on with drum rolls when their instrument valves froze at a Lincoln Memorial ceremony, who fainted in the January chill at welcoming ceremonies for a visiting head of state last year, who withstood the repeated charges of 10,000 frenzied children at White House egg rolls and who bravely accompanied the colors into a thousand stultifying Washington banquets?

Well, apparently they're still with us; the Leominster retreat was all a mistake. "The band could, and in my opinion should, have marched in the parade," said Col. R. C. McInteer, chief of staff at Parris Island, by way of apologizing to Leominster and implying it won't happen again.

So rest assured: service in the corps continues to be a mark of honor and its members shields of the republic -- rather than just a bunch of guys who are afraid to go out in the rain or damage their government-issue instruments because they might not get new ones under Gramm-Rudman. We're glad the brass moved quickly to still the clashing of symbols.