The Market Street El thundered overhead. A large man approached a rowhouse in the 5500 block. He had hair like Cosmo Kramer from Seinfeld, wore low-slung white jeans and a bright red polo shirt buttoned geekily to the neck, and was carrying a metal briefcase.

The man knocked on the door. Waited. No answer.

But as he walked away, the wary resident peeked out from behind the off-kilter slats of venetian blinds. After checking this stranger out, the man opened the door.

"Can I help you?"

"Hi! Sorry to disturb you. I'm Steve Powers. I'm an artist working with the Mural Arts Program." Powers proceeded to explain, rapid-fire, that he and a team of artists and community organizers were going to be doing an ambitious project in this West Philadelphia neighborhood.

A love story, mostly words instead of images, to be painted across the upper stories of buildings along the train line. SEPTA riders will be able to read the narrative as they travel west between 46th and 63d Streets. Another story arc will proceed on the eastbound side.

The man nodded. "OK."

Powers handed him a pamphlet about the project and invited him to attend a community meeting where residents will be able to submit their ideas. Talk about their own love stories. And help decide how the murals will look.

"Hope you can come," he said. As he walked away, the man called out. "We've got Dr. J!"

While mural projects always have their critics, these public art projects are mostly welcomed, particularly in areas where abandoned and neglected buildings mar the cityscape like missing or rotted teeth.

Since the city's Anti-Graffiti Network got going 25 years ago, dozens of walls throughout West Philadelphia have been transformed from rutted stucco and pitted brick to enormous, bright images of gardens, portraits of community leaders, and icons like Dr. J - Julius Erving, the revered Sixers star.

Lately, the Mural Arts Program has been evolving at an increasingly rapid pace, and new projects, such as Power's brainchild, "Love Letters," are going beyond mere two-dimensional paintings.

"We're going to set up a Web site where people can tell love stories, what they love about their neighborhood or family," said Jane Golden, director of Mural Arts. "We want people to send in postcards, love letters, and we'll have an exhibit of them."

Scoping out the walls for the murals, Powers and two other project managers have been riding the El for months, noting when the train slows and speeds up and mapping the best walls.

The story will unfold in the style of the old Burma Shave ads.

Dropping off fliers and recruiting residents to participate, Golden headed east on Market with Powers and three other managers of the project Wednesday. The team surveyed an abandoned building with a faded Uneeda Biscuit sign painted on the wall.

"Pure warehouse," Powers declared, peering into the wire-webbed windows. "The only problem would be electricity."

As part of the project, which is expected to begin in July, the team plans to set up a sign-painting enterprise, hiring as many young people from the area as possible. "So it is a jobs program, as well as a jobs-training program," Golden explained.

The idea, which Powers said had come to him "from the ether," includes a flip-book of the stories and a docudrama, with a script Powers will write.

"This is where I started," he said. He grew up in Overbrook and as a teenager in the 1980s became one of the city's most prolific graffiti writers, with the tag "Espo." Later, he moved to New York. He now lives in Greenwich Village, but wanted to come back to some of the walls he spray-painted in West Philly to create art that is uplifting and hopeful.

"I thought this is my chance to put something on these rooftops that people would care about."

The neighborhood welcomed him and his team this week.

Eagerly accepting the offer to work with the sign-painting initiative, Everett Carvalho said, "Hand-painted? That would look so much better!" Carvalho runs a small computer training center next to the construction site for the Church of Faith House of Prayer & Praise.

Tyrone McGarrell, an aspiring artist who earns a living rehabbing homes, followed the team half a block to ask about the project. Then he went home to get his sketchbook and show Golden his drawings. Looking at a pencil sketch of a hawk, she said, "Oh! "That's gorgeous!" and encouraged McGarrell to join the team that will paint the love letters.

A few doors down, Davis Emmanuel, a retired SEPTA operator, took a pamphlet from Powers. "I think the murals are wonderful," he said. "Messages of love? Well, we can use that around here!"