Arriving in rented Lincoln Continentals before Saturday morning's rehearsal, young men dressed in severe suits, white shirts and bow ties swarmed over every inch of Reynolds Auditorium. "They unscrewed everything that could be opened up and then got down on their backs and looked at the underside of 1,700 seats," said the stage manager, Artesa Bohannon. "I've never felt so safe in all my life."

Indeed, members of Mr. Farrakhan's Fruit of Islam -- some of them from as far as California and all studiously courteous -- stood warily throughout the day and night at entrances, stairwells and doorways. A phalanx of 24, erectly at attention, shielded Mr. Farrakhan's postconcert exit to his car. Many of the musicians played for expenses, but Mr. Farrakhan and his entourage paid their own way. Given the fact that personal attendants probably outnumbered the orchestra, it must have cost someone a pretty penny.

Can Louis Farrakhan play the violin? God bless us, he can. He makes a lot of mistakes, not surprising for a man who had virtally abandoned the instrument for 40 years and has only owned one since 1974. Yet Mr. Farrakhan's sound is that of the authentic player. It is wide, deep and full of the energy that makes the violin gleam. His thrusting sense of phrase has musical power to it, even though some of the erratic movement kept Mr. Morgan and his musicians scrambling at times. Some Large Bodyguards

Mr. Farrakhan arrived at a private home this morning with members of his family and some very large bodyguards. Resplendent in a double-breasted suit, he talked of reconciliation with America's Jews and in terms that seemed, if not desperate, at least terribly urgent. The home was that of James Fowler, the business manager of The Winston-Salem Journal, an arts supporter and a tireless promoter of this event. Mr. Fowler is white.

Mr. Farrakhan acknowledged the symbolism in his playing of music by a European Jew, although he also said he had not known Mendelssohn was Jewish until two years ago. (The Mendelssohn family converted to Christianity.) He plans to repeat the Mendelssohn performance on May 17 in Chicago, both to acknowledge his 60th birthday and to send out more ecumenical messages. This concert is planned to be held in a Christian church and a cantor has been invited to take part. Mr. Farrakhan said the Mendelssohn might be repeated around the country "eight or ten times more." Speaking in a quiet but insistent voice, he said he would "try to do with music what cannot be done with words and try to undo with music what words have done."