Nancy Zeltsman founded the Zeltsman Marimba Festival in 2001. Prominent composers write original pieces for the event.

By VIVIEN SCHWEITZER

“The marimba is coming of age right now, and you can’t throw a dead cat without hitting a marimba concert, the composer and guitarist Steven Mackey said the other day. Until recently only a handful of classical performers specialized in this exotic instrument, but now there are virtuosos, festivals and international competitions dedicated to bringing it out from the shadows of its more established orchestral colleagues.
In comparison to concert-stage stalwarts like the violin, the marimba has a paltry solo repertory. Nancy Zeltsman, a pioneer who began playing the instrument seriously in the mid-1970s, is determined to change that. The Zeltsman Marimba Festival, which she founded in 2001, has commissioned composers like Gunther Schuller and Louis Andriessen to write new pieces, some of which will be performed at this year’s event, which began July 6 at the Colburn School in Los Angeles.
The marimba, with its origins in Africa and an early history in Guatemala, has wooden keys laid out like those of a piano and struck with mallets. Metal resonators below the keys give it a richer timbre than that of its closest relative, the xylophone .
Mr. Mackey, who was writing a work for the festival, cited incredible advances in building marimbas in recent decades.
“They are now beautiful-sounding, resonant, warm, rich things, he said.
The marimba began appearing as a solo vehicle on the concert stage in the 1940s, although recitals featured mostly transcriptions of music written for other instruments.
In the late 1960s and early ‘70s the Japanese marimba player Keiko Abe gave milestone solo recitals in Tokyo . Her recordings, said William Moersch, the chairman of the percussion department at the University of Illinois, “inspired a whole generation of young students in the United States in the 1970s to look at the marimba in a new way.
Composers also began to view the instrument in a more positive light after improvements were made, including an expansion from a four- to a five-octave range, extending to a low C known as the cello C. “That low C can have a very clanky sound, a very beautiful soft sound or a very dramatic sound, said Robert Aldridge, another composer who has written for the marimba.
But the instrument’s increased size also added to its unwieldiness. “Unless you have long arms like a gorilla, Mr. Schuller said, “there are few people who could play the lowest and highest notes. I’ve seen marimba players when they practically have to fly three feet to the right to get that high note.
Even with continuing improvements to the marimba, Ms. Zeltsman said, she is “reluctant to say this is a fully developed instrument.
Adam Sliwinski, a marimba player and member of the ensemble So Percussion, said, “We are still in maybe the adolescence, if not the youth or infancy, of the instrument.