Bringing elongated improvised jams and fresh tracks off their new album, Mantis, next Wednesday’s Umphrey’s McGee show at the House of Blues should be a memorable one. In fact, the memory may have to last you a few years. Their last Vegas show at the 2005 Vegoose Festival was said to be one of their best, but it took the Chicago-based band four years to schedule a return visit. After next week, who knows how long it will take the sextet to get their act back into the Vegas Valley. UM guitarist Brendan Bayliss caught up with the Weekly to discuss the art of stomach drumming and just when to end a 25-minute jam.

Your band is compared to groups like Phish, The Grateful Dead and Pink Floyd. Which of all of these comparisons do you think is accurate?

The thing about us is we kind of jump all over the place. I feel like we can be heavier some nights and funkier some nights. So the whole thing about being labeled can be kind of misleading. In one regard, it’s kind of a pain in the ass, because some people think that you’re going to sound a certain way and you really don’t. At the same time, to be compared to someone who is fantastic and successful is a good thing.

What’s the longest song you have ever played live?

We have a couple of songs that have about 10 minutes of structure. And then with all the improv, you can get up to probably 25 minutes. I’m not a mathematician, but I figure we can get up around there. We’ve been doing this for 11 years, I’m sure we’ve gotten there before.

You’re very into improvisation, but what is your actual song writing process like?

It is unique song to song. Sometimes a song will be finished completely by whoever wrote it, and sometimes someone will bring in just a skeleton that everybody fleshes out together. Then sometimes someone will bring in just a section or a part and someone will glue it together with something else. We call that Legos, where everyone just brings in the little pieces.

With all the improvisation that goes on, do you ever wonder when to stop and let another band member solo or when you should all get back to the chorus?

That’s a constant struggle because sometimes when I might think we have gone too far and we need to bring it back, someone else is thinking, “Oh, this is what I live for. We need to keep going.” You have to do a good combination of closing your eyes and listening and also making sure you’re making eye contact with the other people and reading their body language.

You’ve been with the band since the beginning. What has it been like keeping the project going for 12 years?

There are times when I just can’t believe it’s still happening. When we started this I was 21 years old, a senior in college. I had no idea what I was going to do with my life. I just knew I wanted to do something involving music. I studied English and philosophy.

That sounds like a good background for a musician.

Or for deep thoughts about unemployment. One of the two. I never would have thought I would be doing this so long. It was a combination of luck and effort and surrounding ourselves with the right people. Now, for me, I’m just trying to sit back and enjoy it.

The band is so pro-taping that you provide free tickets to tapers if they will distribute the songs later online. Do you rely on concert revenue mainly or is there still a demand for CDs?

We don’t really make a lot of money from CD sales. The bulk of our income is from touring and selling tickets. Giving away the recorded shows is the best advertising. If they like what they hear then they’ll buy a ticket and that’s where we’ll actually see money.

What is the most unusual instrument you guys have used in your music?

We’ve used our stomachs as drums. We sat around in a circle and when you line people up in a circle and put people at different distances and you all play at the same time, it doesn’t really sound the way you think it does. It depends on if you’re full and you hit your stomach and you hear the water in it, or if you’re slapping it, or you can get bass out of it. We’ve never done it live, just in the studio.