At a time when many bands are struggling to stay relevant after media hype leads them to be prematurely called “the next big thing,” the British alt-rock band Arctic Monkeys is defying the trend.

They stunned the world in 2006 with their debut album, “Whatever People Say I Am, That’s What I’m Not,” and now, only three years since it came out, it’s already considered a classic British album. Its witty observational lyrics, fiery guitar hooks and pure energy caused them to stand out in the cluster of new bands.

Arctic Monkeys’ third album “Humbug,” released on Aug. 19, may just be their most important album yet. While their first two albums were instantly gratifying and accessible, “Humbug” has shown a more mature side of the band. The songs are darker and moodier, and in some aspects you could even call “Humbug” a harder, louder record. This could be due in part to the album’s production by Queens Of The Stone Age front man Josh Homme.

The album’s first single, “Crying Lightning,” is a pretty good indication of what to expect from the rest of “Humbug.” It doesn’t grab you immediately, but the more you listen to it and spend time with it, the more it grows on you. You begin to notice new things. Certain lyrics jump out and you hear new layers of instrumentation. Next thing you know, it has 65 plays on iTunes.

“Humbug” isn’t a complete desertion of the band’s core sound. Rather, “Humbug” displays the band’s progression to a new and exciting level. Alex Turner’s singing has transformed into more of a tender croon. There is more of an emphasis on backing vocals, which becomes a hidden strength. On tracks such as “Potion Approaching,” Turner allows bassist Nick O’Malley and drummer Matt Helders to join in, vocally adding a different aesthetic to the band’s sound. Guitarists Jamie Cook and Alex Turner have more confidence in playing bigger, bolder guitar solos.

The most important observation to make when listening to “Humbug” is that their musicianship has grown greatly. Now they play their instruments with unified confidence and prowess. Matt Helders’ drumming is one of the more overlooked parts of the band. He is practically the backbone of songs such as “My Propeller” and “Dangerous Animals,” driving them to their highest points. Alex Turner’s lyrics are still as sharp as ever, solidifying him as one of the best songwriters of this generation. The album’s standout track is the wonderful ballad “Cornerstone,” which could be the band’s finest moment yet.

When looking back on “Humbug,” the main focal point is that the band is growing. Some people may find that this is their favorite record; on the other hand, some may be disappointed by their new sound. But no matter how you look at “Humbug” it is safe to say that Arctic Monkeys have a bright future ahead of them. They are progressing as a band and they can only get better. This isn’t a perfect album, but its faults can be forgiven by the risks that they do take.

They certainly have lived up to the hype, and they have only been around for four years. Their best is yet to come.