The first half of his 40-year career was spent paying dues - playing pop covers and country, and serving as a sideman for blues greats such as John Lee Hooker. But those years helped mold Trout into a confident blues craftsman, unapologetic about the kind of music he makes.

"I have to do for me what I think is my best work," said Trout, during a telephone interview. "I can't have my work governed by what critics think."

Trout's four-piece band, Walter Trout and the Radicals, goes on at 8 p.m. Friday, June 1, the final act on the opening night of the 12th annual Western Maryland Blues Fest. Bushmaster and The Rhythm Kings kick off the blues weekend at 11:30 a.m. today with concerts at University Plaza in downtown Hagerstown.

The festival wraps up Sunday, June 3, with a free afternoon of music at Hagerstown's City Park.

Friday and Saturday's shows will be in a fenced-in parking lot in downtown Hagerstown. Guitar player Joe Bonamassa is set to headline Saturday's slate.

By the end of the festival, 19 bands will have performed.

How Trout got started

Trout's show is part of a global tour promoting his most recent album, "Full Circle" (Ruf Records 2006), mostly an album of duets. He plans to record a live album and, in January, will do another studio album of originals.

Trout has released 15 albums since the late '80s, a long way from his start as a 17-year-old playing pop covers with the Wilmont Mews, a Jersey Shore band, in 1968. The Wilmont Mews would often battle other bands during their shows. One night, Trout was convinced he could outplay the young guitarist in a rival band called Steel Mill. "But it turns out that guy was Bruce Springsteen," Trout said. "I guess he told me."

Trout eventually moved to California, but he found it hard to get gigs playing the blues, the genre he liked most. The first band he joined in California was a country band called The Jive Bombers. By the late '70s, Trout was playing with other bands and getting attention. That's when he started working as a sideman for blues artists, a job he found to be quite lucrative. Trout played with Finis Tasby, Pee Wee Crayton, Lowell Fusion and John Lee Hooker. "I always thought the secret to being a good sideman (was that) you need to immerse yourself in (the band leader's) style," Trout said. "You can't just whip into a Jimi Hendrix solo. You have to fit into their interpretation of music."

Finding his own voice

Trout still found time to play his own brand of the blues. He performed original stuff at a neighborhood bar in Huntington Beach, Calif., where he was part of the bar's house band. "That's where I really explored who I am," Trout said. Years working as a sideman paid off, as Trout could pull from a variety of styles when creating his own music.

By 1989, Trout went solo and formed the Walter Trout Band, releasing his first album, "Life in the Jungle," that year. After several subtle name changes, Walter Trout and the Radicals was formed in 2000. The band performs in at least 200 cities a year, with stops across the globe - including parts of India.

A shared sound

Trout collaborated with fellow Blues Fest musician Bonamassa on "Clouds on the Horizon," a song on Trout's 2006 album "Full Circle." "I think he's one of the best there is," Trout said of Bonamassa. "He's just an awesome player. I was really excited to have him on the album." Trout said they co-wrote "Clouds on the Horizon" on the spot during a studio session. Then, someone hit record the first time they rehearsed the song. That's the version that ended up on the album, Trout said. "The sound was so good, that was the first and the last time we ever played that song," Trout said.