For the final concert of their 50th year, the Canberra Youth Orchestra will share the stage with Australian jazz legend James Morrison.

"It's their 50th anniversary. It's their final one. It should be great," Morrison says.

"I'm a supporter of youth orchestras and educational work ... I play with student orchestras around the world."

Morrison and his jazz rhythm section will be backed by the orchestra in arrangements of Latin American numbers and selections from some of the great American songwriters, a number of which featured on his album The Great American Songbook, which won the 2017 ARIA Award for Best Jazz Album.

"Gershwin classics, Cole Porter, Johnny Mandel's The Shadow of Your Smile - great songs like that," Morrison says.

He's had the arrangements prepared especially for this concert by Australian and international musicians including Melbourne-based Joe Chindamo and Mark Nightingale from the BBC.

The orchestra and conductor will have to be comfortable with Morrison and his group improvising on the tunes as that's the nature of jazz but Morrison doesn't foresee any problems.

"I work with many youth orchestras around the world and they do a brilliant job with this. Youth orchestras are in some ways not as set in their ways yet, they're more open to things to a greater extent."

Conductor Leonard Weiss certainly seems up for it. He's excited about finishing the orchestra's year with a concert featuring the internationally renowned Morrison, whom he says will showcase his skills on more than just his trademark trumpet and in a variety of styles.

In addition to the Morrison section, the concert will also feature two major 20th-century American concert works, George Gershwin's An American in Paris and Aaron Copland's Applachian Spring.

The orchestral suite Appalachian Spring (1945) was arranged for a larger orchestra from the original 13-player ballet Copland had completed the previous year for dancer and choreographer Martha Graham about a 19th-century pioneer community. Its best-known section is probably the variations on the Shaker theme Simple Gifts.

"The opening is a long string chord and clarinet," Weiss says.

"It's very emotionally raw, very sparse in places

"An American in Paris was jazz-inspired.

"It has a slightly unusual orchestra with four car horns, three saxophones and a huge percussion section."

The 1928 concert piece was inspired by the time the composer had spent in the French capital and was intended to evoke the street noises and atmosphere of the city as well as the bout of homesickness experienced by an American visitor to Paris before the city's charms and power prevail.