Ad filmmaker P Jayendra's office Real Image buzzes with activity. On the walls are huge posters of A R Rahman's Unity of Light concert slated for February 21 in Chennai. You get the impression everyone at Real Image is working with one aim: to make the Rahman show a huge success.

More than the concert it is the cause behind it has them charged.

All proceeds from the concert will go to the Mahesh Memorial Trust created by some of Mahesh's close friends, which include Jayendra, filmmaker Mani Ratnam, actor Kamal Haasan and cricketer K Srikkanth.

Mani Ratnam knew Mahesh from college; Jayendra from school; Kamal Haasan after Mahesh composed music for Nammavar.

Mani Ratnam simply fulfilled a close friend's wishes when he requested Rahman to perform in Chennai.

Mahesh died of cancer a few months ago at 47. Jayendra remembers Mahesh was depressed when he was first diagnosed with cancer in 1989. To help him get over it, Jayendra asked him to pursue whatever he loved most: music. Mahesh chucked his management job, joined Real Image and started composing jingles.

In his short career as composer, he composed over 400 jingles; one film Nammavar, which fetched him a National Award; the background score for P C Sreeram's Kuruthippunal and Kamal Haasan's Aalavandhan, before he died.

Jayendra, the driving force behind the trust, says Mahesh's positive approach brought all of them together to form the trust. When he died, Mahesh wrote in his will that he would like his friends to do something for cancer, especially for poor, cancer-afflicted children.

"At the memorial service for Mahesh, everyone was visibly moved and upset thinking of Mahesh as a person. All of us thought that that feeling should be channelled into something positive. That is how the trust came into being. But we had no idea where we would raise the money from. Suddenly, we thought of Rahman's concert, and Mani Ratnam said he would convince Rahman," Jayendra remembers.

Rahman didn't need convincing. He had lost his father to cancer. At a recent press conference, Rahman said he was doing it for his father and Mahesh. He had no plans to perform in Chennai at the time Unity of Light was conceived. In addition to performances in Kolkata and Hyderabad, he was to tour Los Angeles, Toronto, London, New York and Dubai. After Mani Ratnam spoke to him, Rahman changed his plans and accommodated Chennai in his calendar.

Chitra, Mahesh's wife and one of the trustees, remembers that a couple of days before Mahesh died, he called Srikkanth to the hospital to discuss ways to raise funds for the Cancer Institute. "He was discussing all this while blood transfusion was going on. Unfortunately, he died after two days," she says.

The trust wants to create awareness among people through screening camps that some types of cancer, if detected early, are curable. The most important thing the trust wants to do is help cancer-afflicted children who come to the Cancer Institute in Chennai.

"Mahesh was so positive in spite of cancer," Jayendra says. "That is what saw him through. We want to pass the positive feeling to other people in addition to raising the level of awareness and helping the poor."

"They [Ratnam, Jayendra and Rahman] are all very busy people but they have kept everything aside to give priority to this show," Chitra says emotionally. "They don't have to do it, but they are doing it for Mahesh. If Mahesh is seeing this from somewhere, he will be touched!"

Non-resident Indians who want to gift tickets to their relatives in Chennai can do so at www.giftshakthi.com