Musicians are preparing for this weekend's Porchfest in Arlington, Massachusetts, an event that's taken months of planning to get right.

"We take care of all the logistics of it and we help promote it so that on June 21 this year, we'll have more than 300 performances from literally one end of town to the other," said Tom Formicola, the executive director of the Arlington Center for the Arts. "It is a really joyful day."

Between March and May, residents, business owners and nonprofits register to become Porchfest hosts.

"I think of the hosts as sort of the true organizers," said co-founder Bruce Hoppe. "We are sort of the promoters and the facilitators who let them have 150 parties."

Carol Band has been a host and performer since the event began eight years ago.

"You get to meet all kinds of people in here, all kinds of music and when you're hosting, it's like they're guests for just a few hours in your home and it's wonderful," said Band, who called it the highlight of the year in the city. "I'd call it a town-wide block party. Spirits are high, the music is everywhere, drifting out."

"What's really exciting as a musician is to see audience response to what you do and then echo it," said performer Conrad Warre. "And I find myself focusing on the audience and looking at something and going, 'They're really interested in this. We should do more of that.' It's a great event. Very family-friendly and it's nice to play to kids for a change."

The best part?

"It's free in every possible way," said Formicola. "The bands don't pay any fees, the porches don't pay any fees, the audiences don't pay any fees."

The Arlington Center for the Arts has a website detailing all of the porches and bands, so your day can be mapped out. It all starts at noon on Saturday, with a rain date Sunday.

Previous Porchfests were already held this year in Somerville, Dorchester and Medford.