Following trends works great for cover bands and I'm all for it, but for originals bands I'm not so sure. I don't know if you can try to play what's trendy and popular today and succeed. By the time you master the style and get a bit of name recognition it'll no longer be marketable. You gotta start playing what will be popular two years from now. Of course nobody knows that, so you might as well play what you like and hope it's popular two years from now, but...
How likely is it for a new, young rock band to break into the business on any significant level, though? Granted, looking at the 25 top-grossing tours of last year I was surprised at how much rock there was, but it was nearly all classic rock bands that have been around for well over a decade... Foo Fighters, Bon Jovi, U2, Journey. The only rock band that got popular after the year 2000 might be Kings Of Leon. All the other recent names on that list are pop and hip-hop.
Please don't take this the wrong way, because I mean it constructively, but if I had a dime for every "undiscovered" rock band who scrapped a plan because it's not what a $100M/year rock band does...
You and I wish we had the problems that U2 and Bon Jovi has.
The idea that "once you get your name out there, you'll no longer be marketable" is silly. You and I WISH we had this problem. (BTW, U2 reinvents themselves just as much as Madonna, who rode the coattails of Nicki Minaj, MIA, Cee Lo, AND an acrobat at the superbowl halftime show.)
You need to sell out your own local shows like clockwork. If you can't get it done locally on your own, then you're just one more band that can't draw a crowd. It doesn't matter how special or unique or artistic your music is. If you can't get 50 people to your show, the business stinks. The art might be phenomenal, but the business stinks. There's no money to pay an agent or a manager or a PR team if you can't sell out like clockwork.
So step 1) You must hit critical mass on your current level. If you want to do this with your own unique brand of trend setting music, be my guest. I think you'll do better by ripping off MUSE, The Black Keys, TV on the Radio, Vampire Weekend, or any other current, trendy band. (Remember, we're trying to be a commercial success. Critics can choke on poison.) ANYTHING is fair game. Strippers on stage, body painting, raffle prizes, throwing knives, magic tricks, charity events, dunk tanks, free CDs, human sacrifice, ANYTHING to sell tickets. GET AN ACROBAT ON STAGE, that's what Madonna did.
Step 2) make it stupid for promoters at the next level to ignore you.
Step 3) Repeat. Reinventing yourself will be required.
Most bands never reach a critical mass on the local level. They're too busy making special, artistic music and can't be bothered to sell out their shows. You must work at this EVERY DAY, and work harder than the next band.
Did you call the local college radio station today and tell them about your next gig? Did you invite someone from the local paper to your next show? Did you book studio time on your own dime to record your next single? Did you write a new song? Did you finish a song? Did you practice your stage show? Did you buy new clothes to wear? Did you design new graphics? Did you post on facebook about your next gig? Did you record a video of your band hanging out being funny and post it online? Did you send your CD to a website for review? Did you go busking? Did you tell a stranger about your band? Did you order fliers for your next show?
If you want to sell out your shows like clockwork, you have to work harder than the next band. The other guys are doing all of these things. Every day that passes by without doing this stuff for yourself isn't merely a lost opportunity, it is a set back.