We thoroughly enjoyed watching the Fourth of July fireworks display from the steps of the Lincoln Memorial. However, for several hours before the display, thousands of spectators were subjected to aggravated vocal assault by a hard rock group at Constitution Avenue and 22nd Street.

The leader of the group was foul-mouthed, haranguing all within earshot, many of whom were visiting the Vietnam Veterans Memorial. The performers exhibited little talent and taste, the music was loud, uneven and dissonant, in our judgment without artistic merit or purpose.

The group's immediate audience consisted of a group of punks and apparent "druggies" as well as other nonconformists.

We do support the rights of free assembly, free speech and legitimate rights of protest. However, most who attend functions such as a Fourth of July celebration expect a congenial, festive and family atmosphere, not obscenities. All in all, it was a bad scene.

We're curious about how this group obtained permission to perform, who gave permission and what criteria were used to determine its legitimacy, competence or objectives. It appears that no officials had, or chose to exercise, the authority to pull the plug on them when they became offensive. Doesn't the public also deserve a degree of consideration?

Let's return to more traditional and inspirational forms of celebrating the Fourth of July. JIM PHILAPY ANN PHILAPY Rockville

Each July 4 the crowd celebrating on the west lawn of the Capitol is unique. Who could forget the year Trivial Pursuit was to be found on just about every blanket? This Fourth proved to be a bit different in that no particular interest stood above the others. Yes, there were a few "Scruples" games in action but no other distinctive pastime. Just the usual casual conversations struck up with blanket neighbors and a handful of "bubble blowers" teasing the crowd with wet surprises.

There was one unscheduled highlight of the evening however. During James Conlon's magnificent performance of Dvorak's "New World Symphony" down in front could be seen a little red-headed boy with baton (stick?) in hand furiously directing along with the maestro. His dazzling performance went on until at the finish someone lifted him in the air. "Let's hear it for the kid!" someone exclaimed.

We who were witness to this unexpected treat stood and gave the half-pint conductor a rousing hand. What fun! And, oh, how American! BONITA B. COTE Gaithersburg

I noticed in the Metro section {July 6} references to the trash mess left by July 4 revelers on the Mall and feel compelled to respond to those poor Park Service workers who had to clean it up.

The Park Service got what it asked for. I was on the Mall that evening and can attest to the fact that there was a dearth of trash containers. When I looked around for a place to deposit my refuse, I found only a few, puny overflowing baskets. The most conscientious people in the crowd were forced to make unsightly heaps around them.

There were plenty of Metro trains and portable johns this time. Next year, how about a few more trash receptacles too? ALISON L. EDWARDS Silver Spring