February 10, 1984

SOME 200 years ago, Mozart, writing to his father, referred to the pipe organ as ''the king of instruments,'' and the characterization has clung ever since to this biggest, most complex, most expensive and, for some, the most mystifying of musical instruments. Through the centuries, these ''kings'' have been been created, used and preserved mostly by churches, and opportunities to hear a fascinating variety of them abound in New York churches every weekend. But this weekend, as happens occasionally, another opportunity is available. Tomorrow night, there will be an organ recital at Alice Tully Hall, one of the city's two concert halls that have pipe organs (the other is the Metropolitan Museum's Rogers Auditorium). The recital on the Theodore Kuhn instrument in Tully Hall will be played by Fred Lallerstedt. The program will offer Mozart's Fantasy in F minor, Mendelssohn's Sonata No. 4, Franck's ''Grande Pi ece Symphonique,'' Haydn's Organ Concerto in C (with a chamber ensemble) and David Loeb's ''La Passacaglia Nuova.''

An important link between a cancer gene and a natural substance that promotes cell growth within the body has been discovered by a team of scientists in Israel, Britain and the United States. The discovery was reported yesterday in the scientific journal Nature, which commented in an editorial that ''the result is as dramatic as it will be important'' for research on cancer and on the processes of normal cell growth. The editorial said the work represented ''another leap forward in understanding the basis of cancer.'' Scientists in this country, familiar with the research but not directly involved in it, agreed with that assessment.

American naval gunners fired on Druse and Syrian artillery positions in Lebanon for a second day in retaliation for the shelling of mostly Christian East Beirut. An American Marine spokesman said a destroyer fired about 150 rounds from its five-inch guns. (Page A1, Column 6.) Americans will not be evacuated from Lebanon at this time because of concern that such a move would send the wrong political signal, according to authorities close to the United States Embassy in Beirut. They said an evacuation would upset negotiations aimed at keeping President Amin Gemayel in power. (A10:1-4.)

United States naval gunners bombarded anti- Government artillery batteries in Lebanon today for the second day in retaliation for the shelling of Christian- dominated East Beirut. The destroyer Moosbrugger fired ''roughly 150 rounds from its five-inch guns at artillery positions in the hills east of the capital'' at about 7 P.M., according to Maj. Dennis Brooks, spokesman of the Marine contingent at the airport. On Wednesday, the battleship New Jersey and the destroyer Caron reportedly firing more than 550 rounds toward Syrian-controlled areas. (The Damascus radio said Syria might be ''compelled to react'' unless the naval fire stops. The statement was broadcast as Syrian leaders met with Lebanese opposition leaders in Damascus. Page A10.)

Paul A. Volcker, chairman of the Federal Reserve Board, said today that he thought the financial markets had overreacted to statements by him and Administration officials that Federal budget deficits could sow another recession. ''I think that's a little blown up,'' he told Congressmen who asked him about Wednesday's 24.19-point decline in the Dow Jones industrial average. ''I think basically the outlook is bright.'' In today's trading, the stock average fell 3.56 more points. (Page D1.)