The Greening of PBS Lawn Concerts : Television: Holiday events in Washington draw 350,000 picnickers and pile up large audiences at home.

Guess which were the highest-rated PBS music shows over the last three years.

They weren’t the star-spangled “Boston Pops Fourth,” “Pavarotti Live From Lincoln Center” or “New Year’s Celebration From Vienna.”

They were concerts broadcast live from the west lawn of the U.S. Capitol on Memorial Day and July the Fourth.

These shows, produced by a husky documentary filmmaker and former shotputter named Jerry Colbert, regularly draw 350,000 picnickers to the Capitol grounds--far more than attend presidential inaugurations there.

More importantly for the struggling Public Broadcasting Service, the concerts pile up relatively large audiences at home. The strong rating pulled by last month’s Memorial Day event with Perry Como, Mel Torme and Leslie Uggams could make it this year’s PBS performance winner--unless it is topped by Saturday’s “Capitol Fourth” show, which features flutist James Galway, composer Henry Mancini, singer Julia Migenes, actress Patti LuPone and the National Symphony Orchestra.

One reason for the concerts’ popularity, Colbert says, is that he is able to get just about anybody he asks to perform. Although he has a modest $765,000 budget for the 90-minute shows (financed 45% by Congress), the stars and technical chieftains generally agree to work for token sums, stay in modest lodgings and travel around town in sedans instead of stretch limos.

“These are top pros, giving something back to their country,” Colbert says. And sometimes there is another factor, he adds: “Like in the old Beatles song: You get some help from your friends.”

A prominent Hollywood contingent provides technical backup for the concerts. Walter Miller, the executive director, and Ed Green, the audio producer, handle the Grammy and Tony shows, among other assignments. Tisha Fine, a Hollywood talent coordinator, helps with booking performers for the concert, and Buzz Kohan, a writer on the Academy Awards and Grammys, has written narration for the Fourth of July concert this year.

Actor E. G. Marshall, an old friend of Colbert’s, will serve as narrator. (Because the 90-minute show is tape-delayed on the West Coast, the broadcast times vary: 7 p.m. on KVCR-TV Channel 24; 7:30 p.m. on KCET-TV Channel 28; 8 p.m. on KPBS-TV Channel 15, and 9 p.m. on KOCE-TV Channel 50.)

High points of the program include LuPone--who starred in “Evita”--singing “Don’t Cry for Me, Argentina” and Mancini and Galway performing a flute duet.

And, before the fireworks go off above the Mall to “The Stars and Stripes Forever,” there will be what Colbert calls a “tribute to peace and freedom” as the National Symphony plays Tchaikovsky’s “1812 Overture” with the help of the U.S. Army Chorus and U.S. Air Force Ceremonial Band.

Originally, Colbert intended to make the piece something of a tribute to symphony conductor Mstislav Rostropovich, a former Soviet dissident who made an emotional return to Russia last year after the collaspe of communism.

But Rostropovich developed a serious foot problem and had to cancel his appearance at the concert. He will be replaced on the podium by Hugh Wolff, the symphony’s former conductor.