The Portland Symphony Orchestra, under music director Robert Moody, obviously spent extra time preparing the Mahler Symphony No. 5 in C-Sharp Minor as a memorial to the victims of the Boston Marathon bombing.

On Sunday afternoon at Merrill Auditorium, the principals of each section, especially the horns’ John Boden, displayed the virtuosity and endurance required by Mahler’s notoriously difficult score, and the ensemble supported them perfectly.

The question arises, however, if all the effort was worthwhile. When considering the first three movements of the symphony, I thought of Debussy’s reply to a pedant who suggested he modulate to another key (I’m paraphrasing): “But I like where I am!” Mahler never stays long enough in one place for the listener to anticipate what’s coming next. All one knows is that the expectation of a resolution to the tonic will always be disappointed, except at the end of a movement, where it will appear as a bang or a whimper, or maybe both.

Mahler’s Fifth is usually considered the first of his “classical” period, but it has as much of a program as any earlier work. I: A funeral march for past loves. II: The bonfire of these vanities. III: A parody of former pleasures, such as the waltz. IV: Intervention of the angel (Alma Mahler). V: Triumph of the new music.

The first is a hodgepodge of influences, from Beethoven’s Fifth through a cacophonous carnival to lyrical references to the “Wunderhorn” songs, ending with a loud pluck of pizzicato. It sometimes became impossible to follow the rhythmical pattern.

The second is a stormy sea in which past vices drown, to the accompaniment of Wagner and Strauss. It has a gentle cello trio, more memories of “Wunderhorn,” a horselaugh on the funereal trumpets and a glimpse of the triumphant final theme. It ends with a pianissimo three-note resolution.

The third is a clever parody of the waltz, including its deconstruction, a la Ravel.

The fourth movement, for strings, is the Adagietto love song for Alma, said to be Mahler’s most memorable melody. I didn’t hear anyone whistling it on the way out of the hall. It is pleasant enough, and atmospheric, but Samuel Barber does it much better.

What makes the symphony worth hearing, especially in a live performance, is the fifth movement, in which Mahler puts aside his program and decides to write music rather than drama. It is a wonder — concise, well developed, contrapuntal and clear, as if his studies of Bach had revealed a new way out of the late Romantic nightmare. It is truly triumphant, and resulted in a well-deserved standing ovation,

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

classbeat@ netscape.net