Maestro Raymond Leppard conducts members of the Indianapolis Symphony Orchestra Monday evening during the Gala Opening Concert for the Faculty Artist Series at University of Indianapolis. (Doug McSchooler for The Star)

Raymond Leppard is back to conduct the Indianapolis Symphony this weekend, and he says the orchestra's sound is heading in "a new direction" since his days as music director.

When Leppard retired from the ISO in 2001 and became music director laureate, he said the orchestra was particularly skilled at playing music of the classical era, meaning works by composers such as Mozart and Haydn.

Lately, when Leppard has had occasion to attend ISO concerts, he has been noticing a somewhat different sound from the ensemble that Music Director Mario Venzago has led since 2002.

"I came to hear the Strauss the other day," Leppard said, referring to Venzago's recent performance of the Richard Strauss tone poem "Death and Transfiguration."

"I find they're playing extremely well, really well. Sometimes I think there are questions of balance. I think sometimes the brass outweigh everything else. . . .

"But they should be heading in a new direction. That's quite right. They have a new music director, and his great strength is not the classical world. They moved into another direction, but it seems that they've got all the technical skills and enthusiasm to follow him."

Leppard will conduct the orchestra today and Saturday in a program celebrating his 80th birthday. The program will feature his longtime colleague Pascal Rogé playing Maurice Ravel's Piano Concerto in G, and the Symphony No. 1 by English composer Edward Elgar, whose music the ISO performed regularly and recorded during Leppard's 14-year tenure.

The British-born Leppard said he requested the Elgar partly because it was on the program the first time he led the ISO in 1984, as a guest conductor at Clowes Hall.

"It only seemed appropriate," he said. "It is superbly written. I don't think there's a (bad) bar in the whole piece, which is more than you can say about a lot of music. It has a wonderful opening tune, which keeps appearing in the most mysterious ways until the final apotheosis. It's a big work, a long work, but I don't think it flags for one second.

"Elgar also has an intellect that's so clever, like Beethoven, that shows the intensity of one's concentration. The scherzo tune becomes the melody of the slow movement, but the scherzo goes by so quickly that you wouldn't know it."

Leppard and the ISO have collaborated on many Elgar works, whether grand or intimate, including the "Enigma Variations," the Cello Concerto and the oratorio "The Dream of Gerontius." They also have recorded the "Nursery Suite."

These days, Leppard claims that he's "trying to slow down a bit."

Slowing down apparently includes heading to London, where he will join the English Chamber Orchestra for an Oct. 31 concert. Then, in May and June, he and the Chicago Opera Theater will perform Handel's "Orlando," a baroque opera about unrequited love, madness and recovery.