If you go

What: Doobie Brothers

When: 8 p.m. Tuesday

Where: Dock Street Theatre, 135 Church St.

Price: Requires $500 membership to Music With Friends, plus $1,500 annual fee for three shows

For more info: www.musicwithfriends.com

Possibly more than any other band, the Doobie Brothers have experienced an unconventional career.

Only The Eagles’ path compares to the Doobie Brothers’ immense early success, significant changes in lineup, considerable shift in style and sound, a second peak of success, a breakup then reunion and makeup, new studio music and ongoing touring.

But even The Eagles never had four guitarists and four drummers — at the same time.

Early influences

The Doobie Brothers were influenced by more than just other musicians, such as the Grateful Dead, Jefferson Airplane and Moby Grape. Founder, singer, guitarist and songwriter Tom Johnston reflected on the northern California scene from the Summer of Love through the mid-’70s that brought about dramatic cultural and social change.

“The reintroduction of the blues to a wide audience brought many new sounds and types of music. All this converging at the same time won’t be repeated and is so different from now,” Johnston said.

‘Which Doobie?’

The most well-known line from the Doobie Brothers’ appearance on the “What’s Happening” television show in 1978, “Which Doobie you be?,” reflected what was happening in the band.

With a constantly changing lineup, the biggest change came in 1975 when Johnston had to leave the band because of health reasons.

With a record contract requiring an album release, Michael McDonald was brought in on keyboards and vocals to supplement singer, guitarist, songwriter and original member Patrick Simmons.

As longtime band producer Ted Templeton was “blown away” with McDonald’s demo of “Takin’ It to the Streets,” the band radically changed its sound from guitar-centric rock to softer, bluesy rock with the keyboards front and center.

The band’s second peak of popularity came with its 1978’s Grammy-winning “Minute by Minute” album and the single “What a Fool Believes,” but constant touring and stylistic conflict caused the band to disband in 1982.

This was not the Doobie Brothers’ end, though, as drummer Keith Knudsen brought them back together for a Vietnam Veterans benefit.

Johnston said, “No doubt, it wouldn’t have happened otherwise.”

With this successful reunion, Templeton suggested the “new old” group cut another album. This generated a Top 10 single: “The Doctor.”

Longevity

With numerous hits at or approaching 40 years, Johnston is proud that “Listen to the Music,” “China Grove,” “Long Train Running,” “Black Water” and “Take Me in Your Arms,” among other songs, have stood the test of time.

“I won’t lie,” Johnston said. “While skill is involved, so is blind luck.”

His rhythmic chord structure and distinctive strumming style led to songs that were instantly recognizable.

“Back then, radio was all-powerful and made the bands and the hit songs. You needed a hook such as, ‘Wo, oh, listen to the music.’ ” Now it’s many more people trying to jam through a much smaller door and it’s so much harder to stand out,” Johnston said.

Not all is in the distant past, as Johnston added, “We have some great newer stuff, too.”

On its most recent album, 2010’s “World Gone Crazy,” the band evokes earlier sounds with lush harmonies, including the first single from the album, “Nobody.”

The video, which can be seen at www.doobiebros.com, impeccably blends the band playing the song in the studio with clips from its earlier years.

Johnston said everyone takes pride in playing, but the key difference is basic: simply practicing.

“Vocal exercises make an immense difference. It is muscular and to keep control, you have to keep strong. The audience deserves it,” he said.

Music With Friends

For the Doobie Brothers upcoming concert at the Dock Street Theatre with Music With Friends, Johnston said the group will play songs spanning the band’s history, including some reworked “old new songs,” a deep cut or two and, of course, the hits.

The concert is the first of three shows the organization will present this year.

“With the Dock Street Theatre being such an intimate venue, the shows feel more like a club than a larger concert,” Music With Friends founder Larry Faber said. “Given the Doobie Brothers high-energy level, this show will be powerful and the music alive even more so.”

Johnston concurred, saying, “Whatever age or demographic, our job is to reach the audience and move them to react.”