There may have been worse musical events in Washington this year than the Metropolitan Opera's road company performance of "Il Trovatore," but they probably were not in that price range.

Picking the best is more complicated and subjective, but a list of the best concert experiences would probably be drawn from the following:

Rudolf Serkin's performance of the last three Beethoven piano sonatas: the year's best offering by the Washington Performing Arts Society and possibly the most impressive performance of the year.

Mstislav Rostropovich's conducting of Tchaikovsky's "Iolanta" and Prokofiev's "Alexander Nevsky," as well as his sonata recital with Rudolf Serkin.

James Levine's conducting of "Parsifal."

The American Composers Series in the Kennedy Center's Terrace Theater.

Messiaen's "Quartet for the End of Time" at the Library of Congress by an international group of young performers.

The chamber music performance in memory of Abe Fortas given in the Eisenhower Theater by a group of musicians that included Isaac Stern, Eugene Istomin, Leonard Rose and Mstislav Rostropovich.

The survey of Mozart violin sonatas played on original instruments by violinist Sergiu Luca and pianist Malcolm Bilson at the Library of Congress.

The Washington Opera's production of "Trial by Jury" and "Monsieur Choufleuri" (to be repeated early next year)--probably the funniest musical event of 1982.

The program given on Stravinsky's birthday at the National Cathedral.

The Stravinsky half of a Bach-Stravinsky program given here by the St. Paul Chamber Orchestra, which will be telecast next month. Also with this orchestra, there was a performance of Mozart's Sinfonia Concertante with Itzhak Perlman and Pinchas Zukerman as soloists.

The visit of the Concertgebouw Orchestra--particularly in Mahler's Seventh and Berlioz's "Symphonie Fantastique."

There were probably more than 100 world or Washington premie res during the year, including a lot of Dutch and Scandinavian music brought in by two festivals and five American orchestral pieces performed at the finals of the Kennedy Center Friedheim Awards. The Friedheim prize went to the powerful, atonal "Avanti!" by Gundaris Pone', with runner-up prizes for David del Tredici and Thomas Ludwig. But the Guitar Concerto of Ivana Themmen and the "Fire Variations" of Domenico Argento were also of excellent quality. In the future, the Argento work may well be recognized as the best of the lot.

The most unusual new music of the year was "200 Cellos" by Lukas Foss, given its world premiere at the First American Cello Congress, held at the University of Maryland. The work will probably not be performed very often because of the number of instruments it requires. It produced some extraordinary sounds, but the memory may be effaced next year when the University of Maryland sponsors a tuba festival.