Edward Elgar's unadulterated creativity hit its peak with his "Enigma" Variations of 1899. Each variation is a portrait of one of his friends or family. Cues are placed at the beginning of each movement, such as C.A.E. for wife Caroline Alice Elgar, the famous "Nimrod" for his publisher, August Jaeger, and the last depicting the composer himself.

But Elgar's most original work may be the Cello Concerto in E Minor. Completed in 1919, its melancholy ambiance and emotional underpinnings are stunning. "It is a very personal piece," says Leonard Slatkin, who will conduct the work this weekend with Anne Martindale Williams soloing. "But it also for Elgar is a more restrained piece than his other works at the time. It is almost like a piece of chamber music." Speculation continues as to whether Elgar wrote it in response to a paramour or to the senselessness of the Great War, though scholars tend to doubt both.

		Anne Martindale Williams The PSO performs Elgar's Cello Concerto at 8 p.m. tomorrow and 2:30 p.m. Sunday and his "Enigma" Variations April 18 and 20 at Heinz Hall.

"There's nothing particularly post- (or even late-) war about it," says Harper-Scott. "But it is of course deeply sad, and people do like to pin sadness down to particular things -- not realizing that it is an abstract noun, and that an art capable of great abstraction is a good medium for its exploration."

The concerto opens with potent recitative by the cellist, an anguished outburst that will return at the end of the four movements to indicate that the darkness cannot be eradicated. There were precedents for Elgar's use of four movements in a concerto, but the way he structured them was unusual. "The whole first and second movement are a gigantic set-up for the third and fourth," says Slatkin. "I think of it as a two-movement concerto."

After the recitative, a lilting opening theme emerges, one nothing like the aggressive themes the musical world was accustomed to at the time. This rhythmic line then is interrupted by a dramatic rising scale -- a touching moment seemingly destined to lead to something affirmative. But a second theme abounds with sighs, as if the music is already resigned to its fate. After a "haunting link," (described so by Elgar scholar Diana McVeagh) the second movement is filled with nervous sixteenth notes punctuated by a noble gesture (marked largamente) that fails to assuage the perpetual motion.

The Adagio third movement is deep, mournful and intimate. It is a song for cello, but not nearly redemptive or long enough to dispel the brooding mood. The fourth introduces the most forceful music of the entire piece, as if the concerto is gathering strength to finally rid itself of the yoke of suffering. But it is not to be. The movement "moves through passion and regret to die out," writes McVeagh. Moments later that anguished recitative returns. A coda brings the piece to an abrupt and almost mocking end. "The last movement is really not like anything ever seen before," says Slatkin. "For a piece that sounds like it is going to end positive, it sort of doesn't. The stuff that is leading up to suggest it is going to end in a major [key] and we are all going to be happy and then it doesn't. It ends in a world of tumult actually. I also find it interesting that it has achieved a great deal of popularity for a work that is, for me, very introspective, and that usually doesn't happen."

Another reason the concerto has become so popular is that it captures the power of the cello in all its baritone splendor as little music has ever done. It's no wonder it has long been a favorite of cellists, most famously Jacqueline du Pre. Du Pre's connection with the concerto in the 1960s was so strong that to this day the two are linked in the minds of most music lovers. Her tragic succumbing to multiple sclerosis only added to the association. Also, the Cello Concerto was recorded as early as 1919 -- Elgar was a champion of the recording industry when many others dismissed it -- and that also put it into the public ear early and often.