Martin Feinstein, general director of the Washington Opera, has had a lifelong romance with music which, in turn, has led him to the romance of travel. During his long association with the late impresario Sol Hurok, during eight years as executive director of the Kennedy Center, and now in his present position, Feinstein has come to know many of the world's major vacation spots.

Though he first visited some cities "as a tourist," most of his later travel has been on business trips. "When I go to a city for the first time, whether on business or pleasure, and I have sufficient time, I generally take one of those organized sightseeing tours. Then I go back to the museums and points of interest that I want to expand upon. So I'm a very good tourist." A few of his favorite places:

* San Francisco. "Probably my favorite place to visit. It's an extraordinarily beautiful city and a complete contrast to Washington in many ways. I generally go there for the opera . . ."

* London. "I suppose it all goes way back to my first visit in 1952. You always hear that the British are so reserved. When I got over there I knew some friends in the profession . . . they were open, hospitable and warm, inviting me to their homes . . . Of course I like to go to the opera at Covent Garden, the English National Opera, and to Glyndebourne in East Sussex . The theater is very exciting, too. London has a kind of tradition and history that intrigues me still."

* Venice. "I think we've found the ideal way to enjoy it: take a hotel on the beach on the Adriatic, spend half a day on the beach, and then take a launch and spend the other half-day sightseeing in the city.

* Florence. "I'm very much in love with the city. It just breathes history and art. From the first time I went, which was in 1953, I've always returned with great anticipation because no matter how much you've seen there is always more to see. I suppose I also have a love affair with the Italians. They're wonderfully warm and charming people who appreciate your valiant attempts to speak their language--and you also tolerate from them a degree of inefficiency which you would not from any other people because they are so charming."

* Leningrad. "I had the good fortune to arrive from Moscow on the Red Arrow Express, an overnight train . . . traveling alone without an official interpreter. I arrived early in the morning after the city had been covered with beautiful, clean white snow. I walked around for hours . . . it seems that after you have walked through one series of parks with glorious vistas, you come upon another."

Feinstein has a master's degree in music; his wife, Bernice, has a PhD in the same field. "We enjoy all musical events together. She used to travel with me often in the days of Hurok, one way by ship, combining business with pleasure for about six weeks." But business trips abroad are generally "too hurried these days--two or three days."

Feinstein feels that in contrast to what most people would consider his "glamorous" business travel, "my real vacations would appear to be very prosaic." The couple and their three children have a summer home on Shelter Island, N.Y., with "a lawn that goes right down to the beach. I stretch out in the sun, catch up on my reading, and by mid-afternoon I generally have enough energy to play some tennis. And I don't wear a tie."