It looks like an orchestra, it sounds like an orchestra and it’s even referred to as an orchestra, but actually, it’s just a big string quartet.

Just like most small string ensembles, The Academy of St. Martin in the Fields isn’t led by a conductor’s baton. In order to stay together, the group takes “starting and ending” cues from first violinist Kenneth Sillitto and relies on its inner pulse for the rest.

The Academy of St. Martin in the Fields has been known to the music community as the “world’s most famous chamber orchestra” ever since its founding by Sir Neville Marriner in 1959.

“[The Academy of St. Martin in the Fields] started as a baroque orchestra,” Sillitto said. “[Marriner] cleaned up the way baroque music was being thought of.”

And the ensemble has continued to “clean up” the state of chamber music.

Over the past 40 years, the worldly acclaimed chamber wonder has been devoted to the progression and prosperity of chamber music, setting the standard for aspiring chamber musicians across the globe.

Throughout its crusade, the group has managed to perform everything from Beethoven to Bartok to Britten.

“We’ve encompassed all the repertoire known to chamber music,” Sillitto, 20-year veteran of the orchestra, said.

During Saturday night’s concert in Stephens Auditorium, the 21-member group will perform Henry Purcell’s “Chaconne in G minor for 4 strings,” Bela Bartok’s “Divertimento for String Orchestra,” Wolfgang Amadeus Mozart’s “Divertimento in D major” and “Variations on a Theme of Frank Bridge” by Benjamin Britten.

The orchestra’s stop in Ames is just one of many the group will be making this year.

Sillitto noted that the orchestra tours about six months out of the year to places all over the U.S. and abroad.

And the reason the orchestra is able to score such a large number of concerts annually is not just because it’s so good.

Sillitto said it’s cheaper for venues to hire smaller chamber orchestras instead of larger scale symphonies because symphonies have more instruments to transport and more musicians to pay.

“Most places would love to bring in larger symphony orchestras, but they can’t afford to,” Sillitto said. “That gives us a chance to play some nice music.”

Though all the musicians in the orchestra are highly qualified and respected, they still practice just as hard as a group that tours just a few months out of the year.

“We rehearse for every tour while we’re on tour for every concert,” Sillitto said. “Tomorrow we have a three-hour rehearsal before the concert.”

Despite many hours of tiresome rehearsals and practices, Sillitto said the orchestra will remain committed to spreading quality chamber music, and it will continue to maintain a standard that has been unequaled.

The Academy of St. Martin in the Fields will play at Stephens Auditorium Saturday at 7:30 p.m. Tickets are $19, $16 and $13 and can be purchased at TicketMaster locations.