With this week's Saint Paul Chamber Orchestra concerts, soprano Dawn Upshaw bids adieu to her role as SPCO artistic partner. Heard Thursday night at Trinity Lutheran Church in Stillwater, the event was not a sad occasion, as Upshaw is scheduled to return for concerts next fall.

For her farewell, she chose two pieces of chamber music, the kind of challenging vocal music that has become her raison d'être.

She began with the Ravel song cycle, "Chansons madécasses (Madagascar Songs)" for soprano, flute, cello and piano.

The cycle drew on Upshaw's skills as a musical storyteller. Her warm voice captured the longing for an absent lover and the erotic encounter when she arrives. A political diatribe against white imperialism carried her to the top of her register. She risked harsh sounds to communicate the text.

The instruments created an exotic musical tapestry out of which the voice emerged.

George Crumb described his song cycle, "Night of the Four Moons," as an "occasional" work, written in response to the Apollo 11 lunar landing in July 1969. He found the event unsettling and conveyed that in a unique soundscape for an ensemble featuring cello, flute, banjo and percussion.

There is little lyricism here, but the songs create a strong sense of mystery. In music not classifiable as easy listening, Upshaw gave each song a strong emotional reality, especially when she sang a dialogue between the moon and a frightened child.

Mozart's "Linz" Symphony (No. 36 in C Major) is also an occasional work. He was visiting the city of Linz when the count hosting him requested the performance of a new symphony. Mozart didn't have one, so in five days he wrote this.

It does not feel rushed. In fact, Mozart produced the grandest symphony of his career so far. Throughout, you could hear the 27-year old's self-assurance at his stately composition.

Haydn was 29 when he wrote his Symphony No. 6 in D Major "Le matin (Morning)" that opened the concert. A boisterous work, it's a showpiece for the orchestra, with members emerging from the ensemble for solos.

The second-movement dialogue between violin and cello was only outdone by a third movement duet for bassoon and double bass.

The orchestra, led by associate concertmaster Ruggero Allifranchini, handled both symphonies with wit and verve.

William Randall Beard writes about music and theater.