The Mile of Music is a gem of a festival hidden in plain sight in Appleton, Wisconsin. It’s astonishingly good, especially considering the ticket price: free.

Now in its 10th year, the Mile of Music features 200 performers over four days at 40 venues along a mile of the main drag in Appleton, a city of 75,000 about 90 minutes north of Milwaukee. Artists play multiple times, resulting in some 700 sets.

There aren’t huge names, no headliners, just lots of great bands who haven’t hit it big yet. No cover bands allowed. Styles range from rock to folk, hip-hop to country, Latin to Americana. The biggest names this year were probably the Heavy Heavy, Joshua Ray Walker and NPR Tiny Desk winner Alisa Amador.

I saw 29 artists at the fest, with nary a dud. (Woe to my feet and back.)

My first stop was the Mondo Wine Bar for Americana artist Jessica Pounds. The sophisticate that I am, I ordered a nice red (can of Coke). Pounds is relatively early in her career, with just one recorded song, “Starlight Silhouette.” She was cool and confident onstage, singing in a voice both strong and lilting. Her lyrics are sharp: “You don't have to tell me this isn't love, oh believe me, believe me I know... I'm just a stranger with you in some other woman's bed.”

On the other end of the career spectrum is Steve Poltz. He’s a great songwriter – he co-wrote Jewel’s big hit, “You Were Meant for Me,” and more recently songs with Billy Strings and Molly Tuttle. But he could easily be a standup comedian. He took off his coat, showing off his tie-dyed shirt, and told the story of its purchase. He saw it in a thrift store but worried one of the three guys there would get it first. He asked them if they intended to buy it, and they looked at him and said, “Why are you in our house?” The jokes are good, but so are the songs.

My first attempt to see Wire and Nail was foiled by the humid 93 degrees at the packed outdoor venue, but mostly by Harry and Larry braying about the world's most boring jobs three inches from my ear. Take 2 was much better, and I'm glad I got there. Wire and Nail are a good time party band. You could call it country rock, but I'm going to call it ronky tonk because that's just more fun, and maybe more accurate. Their outlaw country with a rhythm section anchored two miles deep carries hints of Marshall Tucker, but mostly like Waylon turned up to 11.

A few more highlights:

The Sweet Lizzy Project is a rock band from Cuba now living in Nashville (and who all recently became American citizens, singer Lisset Diaz told me after the set). Diaz is a dynamic frontwoman, her powerhouse vocals soaring over the band’s bombastic sound. It’s a little Alanis Morissette, a little Florence and the Machine, a little Smashing Pumpkins, all a fist-pumping, crunchy guitar delight. Their latest album, “Pirate Radio,” is a banger.

Sway Wild might be my favorite discovery, a funky rock-folk duo of Mandy Fer (best known as Allison Russell’s guitarist) and Dave McGraw. Blindfolded, you wouldn’t know there wasn’t a five piece band onstage. That’s due largely to Fer, a virtuoso who produces a cascade of sweet sounds while bouncing all over the stage. In a better world, “Chimney Fire” would have been a big hit.

Angela Perley rocked hard in a twanging-and-banging kind of way, a top-flight bar band with a country flair. There’s no disparagement in the bar band reference – it’s hook-filled music to turn up and raise a toast, guaranteed to kick up the party from an 8 to a 10.

Pegasis played a charming set at an unusual venue: a city bus. The Mile of Music bus takes a 20-minute tour of the city as artists play at the back. It works! It’s cool! Pegasis is a sister act from the Dominican Republic, now settled in Green Bay. Their harmonies are gorgeous, particularly on the wistful “Distancia.”

Lilli Lewis offered a rich stew of New Orleans flavored Americana, her keyboard complementing a lovely voice that’s pure, sweet and strong. “Everyday” started as a slow burn, built to a crescendo, settled into a head-nodding groove, then back up to a rousing finish. Lewis’ music is good for the soul.

Joshua Ray Walker might be country music’s finest young songwriter, specializing in finely wrought tales of life on the margins. Like “Last Call”: “I don't wanna be here when they say last call / Don't wanna see your face when the lights come on / I'm pretty sure you think my name is Paul / I don't wanna be here when the lights come on.” In concert, pedal steel player Adam “Ditch” Kurtz almost stole the show.

I’ll stop there, but there were many more, including Alisa Amador, Adeem the Artist, Anna Rose, Bee Taylor, Girl Blue, Patty PerShayla & The Mayhaps, Making Movies, the Heavy Heavy and Mya Byrne.

I was seriously impressed, like Rolling Stone was last year. Artists were, too. Poltz and Adeem both said they couldn’t think of another free festival of this quality. Maybe French Quarter Fest.

Artists were noticeably enamored by Mile of Music. Numerous artists said how well they were treated, the female artists most notably. “You make me feel safe,” Amador said, noting that that’s definitely not always the case at festivals.

And what a deal: I paid $600 for two tickets each to my last two stadium shows. For Mile of Music, I paid $420 for three nights of a pretty good hotel and four days of parking smack dab in the middle of the fest.

Next year’s Mile of Music is August 1-4.