LOS ANGELES - Among the items the Grammy Museum included in its George Harrison "Living in the Material World" exhibit that opened about this time last year was a letter the former Beatle received after the all-star Concert for Bangladesh fund-raiser he spearheaded at Madison Square Garden in 1971.

The letter was from his friend Ravi Shankar, the Indian sitar master who had sought Harrison's help in raising awareness of the plight of residents of the nation that had recently been devastated by floods and war.

Shankar, who died Tuesday at age 92 after surgery in California to replace a heart valve, thanked Harrison in his letter for his efforts in rounding up some of the biggest names in rock music at the time to bring their celebrity to bear on behalf of people struggling half a world away.

But Shankar also urged Harrison to use his fame to help those in his own audience, advising him to encourage his fans "to stay away from the drugs."

It was an issue that Shankar saw close up after his endorsement by Harrison put him in a new position in the West. In India, Shankar had long been revered as one of the greatest proponents of that country's classical music.

But in the West, he became something of a rock star himself, sharing the bill at the Monterey Pop Festival in 1967 and at Woodstock two years later.

It worried Shankar that new audiences discovering the sublime intricacies of his nation's musical tradition were treating it simply as background music for their drug-induced trips or jam-band instrumental noodling.

Usually, he maintained a sense of humor about the earnest naivete toward instruments, sounds, and performance practices foreign to rock audiences.

As documented on The Concert for Bangladesh album, which won a Grammy as album of the year, he and his ensemble opened the show at Madison Square Garden, at first engaging in low-intensity interplay with one another. Then the music subsides, and the audience applauds.

A smiling Shankar than addressed the crowd, saying, "If you enjoyed the tuning up that much, I hope you enjoy the music even more."

Ultimately, many musical explorers did learn to understand and appreciate the complex rhythms and exceptional virtuosity of Shankar and fellow musicians such as Ali Akbar Kahn and Alla Rakha, who joined him for the Concert for Bangladesh, and his own sitar-playing daughter, Anoushka Shankar. (Survivors include a second daughter, musician Norah Jones, who said in a statement: "My dad's music touched millions of people. He will be greatly missed by me and music lovers everywhere." He had little role in raising her, but they were reported to have reconciled in later years.)

Shankar's success and influence also opened doors for musicians from other countries and cultures, which led Harrison to aptly describe him as "the godfather of world music."

Yet Shankar, who continued to perform as recently as last month, maintained a disarming humility about himself. It was the quality that initially caught the attention of a Beatle who had brushed elbows with celebrities and royalty of the highest magnitude.

"Ravi Shankar was the first person who did not try to impress me," Harrison said in Martin Scorsese's documentary George Harrison: Living in the Material World. That, in turn, is the one thing that could impress a Beatle - and so many others around the world who came to identify Indian music with the man who did more to spread it across the globe than any other.