Umphrey’s McGee is one of the best touring bands in America. Now that I sound like a total groupie, let me explain.

These guys aren’t for everyone. Some of you might not like songs that last four . . . or seven . . . or 15 minutes. Some of you might like your concerts to have a consistent genre. And some of you might not like progressive jam rock.

Well, let’s just say that Umphrey’s McGee is different. The guys don’t noodle endlessly over simple funk grooves. And they don’t cater to the Man with one kind of music. But man, can they jam.

Most of the composed sections leave room for some improvisation. On any two nights, you may hear two completely different versions of the same song.

“Jake the other day made a good comment. ‘We’ve been playing this song for five or six years. Let’s make it a rock ‘n’ roll version tonight,'” said bassist Ryan Stasik. “We change it up so it’s different for us, which translates it different to the audience.”

The composed, instrumental sections of Umphrey’s McGee songs flow more like the score of an orchestra than a typical three-verses-and-a-chorus rock song. Songs take the listener on a journey as the band creates a variety of moods. Sometimes the music is bright and full of positive energy, but more often, it delves into the dark and somber.

The lyrics differ almost as much as the melodiesL: mediocrity in “Slacker,” loss in “2nd self,” even that sickening feeling of being in trouble with the law in “The Fuzz.”

During a show, everyone in the band is fair game for a cheap shot. Anytime the word “old” is mentioned at the end of a lyric, members of the band make a motion towards keyboardist Joel Cummins, who is only a year older than the rest of the guys and happens to be balding.

After drummer Kris Myers joined the band in 2003, he quickly learned the band’s laugh-at-yourself mantra.

“It was pretty much a learned behavior from the get-go. I got used to their sarcasm, pretty much, right away . . . everyone gives each other a hard time, and I could tell that these guys went to college together,” Myers said.

Part of keeping it loose on stage includes playing about the widest variety of cover songs you can imagine. Past Umphrey’s McGee shows featured covers of everything from Warren G to Nirvana. On a more regular basis, they cover The Beatles, Pink Floyd, Frank Zappa, Genesis and Yes. They have even been known to break out Lionel Richie’s “All Night Long.”

Live at the Murat, released last week, is a true-to-form representation of a live Umphrey’s show.

Tomorrow night, Umphrey’s will make its first appearance at the Orpheum Theater.