PORTLAND — When the Portland Symphony Orchestra repeats its romantic spring concert at Merrill Auditorium tonight, try to get a seat.

The last concert of the regular season has something for everyone, including two of the most erotic works in the repertoire.

I heard the Sunday afternoon performance, and it more than lived up to expectations, beginning with the Prelude and Liebestod from “Tristan und Isolde.”

Wagner’s operas are often wordy and overblown – the test of a real Wagnerite is the ability to sit through the entire “Meistersinger” – but in this scene his technique really works, the characters and action are clearly portrayed in music, and the development of a simple motif is almost as good as Beethoven’s.

The subject is the culmination of a love so strong that it can be consummated only in death, and the end result is said to have scared Wagner himself. This is music that when heard live with a full orchestra will raise the hair on the back of your neck. The orchestra did it full justice.

The Liebestod was followed by the charming Concerto for Bassoon and Orchestra in B-flat Major (K 191) by Wolfgang Amadeus Mozart, with the orchestra’s principal bassoonist, Janet Polk, as soloist.

Polk is not a virtuoso but something better, a sensitive musician with a feel for phrasing and the technique to convey her ideas. Her cadenzas explored the full range of one of my favorite instruments, and the overall effect of the piece was light yet satisfying. It might also be called erotic, in a baroque sort of way.

The piece de resistance was the entire score, not one of the suites, of Ravel’s “Daphnis and Chloe.” I expected it to be too long without the visual effects of the ballet, but it easily held the interest throughout. It didn’t need the scene-setting supertitles, but they were useful in stimulating the imagination.

The more I hear Ravel’s music, the more I tend to agree with the American composer Ned Rorem, who maintains that it is the most beautiful ever written. The climaxes are thrilling and evanescent, vanishing into thin air as if an angel had passed by, but never overworked.

“Daphnis and Chloe” outdoes Wagner in overt eroticism, and as a ballet score it almost seems to dictate the choreography. The final bacchanal, in 5/4 time, is one of the most energetic dances ever written. The rhythm makes it, but the original dancers had such a hard time with it that they chanted the choreographer’s name, Ser-gei-Dia-ghi-lev, to keep in step.

The score gave every section of the orchestra, plus Music Director Robert Moody, a thorough workout. The Oratorio Chorale and Vox Nova Chamber Choir performed like two more instrumental sections – very well.

Since no ballet company today could afford the large orchestra and choruses required to fully realize this work, hearing it live is a uniquely thrilling experience. This was one performance that thoroughly deserved a standing ovation.

Christopher Hyde’s Classical Beat column appears in the Maine Sunday Telegram. He can be reached at: classbeat@netscape.net