The best free show on the East End this week is on a farm. The Hallockville Hootenanny returns to Hallockville Museum Farm in Riverhead this Saturday, August 15, with five bands playing from noon to 7 p.m., food trucks and craft vendors filling out the grounds, and no admission charge at all. The farm sits at 6038 Sound Avenue, in the middle of the North Fork's farm belt, and the event is sponsored in part by a Suffolk County grant, which is a large part of why a seven-hour festival costs nothing at the gate.

Five bands, seven hours

The lineup runs five acts deep: Ernie & The Band, Mr. Rooster, Dysfunktone, Westlake and Purely Green. With the music running from midday into the early evening, the day works equally well as a destination or as a stop on a North Fork Saturday that also involves farm stands and wineries.

Food comes from the trucks rather than a concession stand, and the vendor rows lean toward local crafts. Bring what you would bring to any field concert: something to sit on, sunscreen, and patience for Sound Avenue traffic on a summer Saturday.

The venue is half the point

Hallockville is not a festival ground that happens to have old buildings on it. It is a 28-acre museum farm with 19 historic houses, barns and outbuildings, running from the mid-1700s Hallock Homestead to the Depression-era Cichanowicz Farmhouse, and the Hallock family worked this ground for more than 250 years before it became a nonprofit dedicated to keeping eastern Long Island's agricultural history in front of people. On a normal day you can walk the grounds from sunrise to sunset for free and meet the resident livestock; the building interiors open only on guided tours, which run Saturdays from 11 a.m. to 3 p.m. at 15 dollars for adults and 10 for seniors and kids five to twelve.

That schedule overlaps the festival, which is worth noticing. A tour ticket on Hootenanny Saturday gets you inside a mid-18th-century farmhouse while five bands play outside it, which is about as North Fork as an afternoon gets.

The farm's season runs May 1 through October 31, so mid-August catches it at full operation: gardens in, animals out, and the museum shop open weekdays from 10 a.m. to 4 p.m. and Saturdays from 11 a.m. to 3 p.m. Sound Avenue itself is the other half of the setting. The road is the spine of Riverhead's farm belt, and the stretch around Hallockville puts you within a few minutes of the farm stands and u-pick operations that are hitting their late-summer peak right now, which is why the festival works so well as an anchor for a full day out east rather than a single stop.

The rest of the farm's August

The Hootenanny is the loudest thing on Hallockville's calendar this month, but not the only one. The farm's Old Time Jam runs Thursday, August 13 and again August 27 from 5:30 to 8:30 p.m., an open session where musicians of any skill level can sit in. On Saturday, August 22, a free dye pot demonstration runs from 10 a.m. to 2 p.m., with natural dyeing done the way the farm's original residents would have done it, and space is limited. A basket weaving workshop follows on August 29 from 10 a.m. to 3 p.m. The farm also holds its annual gala dinner on August 20 at Giorgio's in Baiting Hollow, and the big one, the Country Fair, lands October 3 and 4.

For a nonprofit that maintains 19 historic structures on admission-free grounds, this calendar is the business model: the free events build the audience, and the paid ones and the county grant keep the roofs on the buildings. It is also why showing up to the free one matters more than it looks. A field full of people on a Saturday is the evidence a small museum farm points to the next time a grant application asks who it serves.

The practical version

Saturday, noon to 7 p.m., 6038 Sound Avenue in Riverhead, free. Rain has not been addressed on the event page, so if the sky looks doubtful, the farm's number is 631-298-5292. If you have spent the summer meaning to get out east and have not, a free festival on a 250-year-old farm, in the middle of peak farm stand season, is the lowest-cost version of that trip you are going to get.