Reprinted from yesterday's late editions.

"Tell me, Mr. Hirshhorn," inquired composer Elie Siegmeister, "why is it that you had to put your money into art instead of music?"

"Well," replied the gnomish art collector-tycoon who among other things has built in this city a major museum of contemporary art, "you know I had a poor childhood and my mother was left with us 10 children and I took piano lessons and the time came when I had to get a job to help out and had to stop taking piano lessons. I tried lessons again in Miami in the '30s, but it didn't take and I went to sculpture at about the same time."

Washington's gain is Siegmeister's loss.

What had brought Hirshhorn to one of his rare social appearances was a gathering here of some of the biggest luminaries of the art world for a session on Capitol Hill on so-called artists' rights legislation. Afterward, one of the chief sponsors, Rep. Fred Richmond (D-N.Y.), entertained them at a party in his home.

Famed artist Robert Rauschenberg was considered more talkative at the party than during the session in the Rayburn House office building, where he declined an invitation to speak on the subject that most concerned him, restoration of tax deductions at full market value for works that artists donate to museums. Deductions have been allowed only for the cost of materials since 1969, a situation that was created unintentionally, former Ways and Means Committee chairman Wilbur Mills was quoted as saying.

"It's outrageous that we can't deduct when everybody else does. You better bet that my estate would pay taxes at full market value. So what are we supposed to do - burn all our works before we die? And they all say our motive is greed. And they say the deductions would help only the rich painters.

"It's that last argument that really gets to me, because I give a lot of my money to younger painters. I'm not hoarding it.

"Also, I haven't always had money." Nodding toward his colleague Jack Youngerman, another noted painter, Rauschenberg said, "I can remember the days when Jack and I had to share a sandwich, because we couldn't afford two."

Noting that painters are getting more political because the government is getting entangled in their interests, Youngerman noted, "It wasn't so long ago that the only reason I had to come to Washington was to demonstrate."

Another artist to add his word to the campaign, in Siegmeister's words, to "go to the mat with the IRS," was Donald Judd, who said the present laws "are demeaning because they assume we create for the money only."

Other proposals discussed at yesterday's session included a "morality for artists" bill that would protest works from alteration or mutilation without the artist's permission and the so-called Richmond bill, which would provide spaces on income-tax forms for checkoffs for the arts and humanities, similiar to the present ones for campaign contributions.

A recurrent rumor at the party was that a choice on the new chairman of the National Endowment for the Arts is imminent and that one of the candidates, Peggy Cooper, founder of the Workshop for Careers in the Arts, is scheduled to see the President today. Reached for confirmation, Cooper said, "I have absoluetly no comment."

At the party, another commonly cited candidate for the job, Livingston Biddle, said, "I have no idea what's going on."

Meanwhile, the outgoing chairman, Nancy Hanks, was asked if she had anything important to say to a party reporter, and replied with a slight curtsy, "Just write that my dress is from Loehmann's."