Undoubtedly affected by the historic, shocking attack on their hometown of New York City, the Beastie Boys got more serious, musically spare and political on their first post-9/11 album, 'To the 5 Boroughs.'

However, while hardly a creative or commercial flop, the album failed to connect with listeners as strongly as the group's previous records.

The somewhat muted reception 'To the 5 Boroughs' received could be attributed to the record's stripped-down sound and relative lack of the band's trademark humor. Of course, the fact that it had been over six years since the trio released their last album -- 1998's acclaimed, triple-platinum 'Hello Nasty' -- probably didn't help either.

Or it could just be, as band member Michael 'Mike D' Diamond put it in a 2011 Interview magazine feature, that "the thing about being around for a frickin’ long time is that you’re not gonna knock it out of the park every time." Bandmate Adam 'Ad-Rock' Horovitz was quick to agree in the same interview: "Maybe 'To The 5 Boroughs' just wasn’t that good. I mean, we thought it was great, but looking back on it, there were some duds on there, so maybe that’s what it is."

Regardless, the band maintains it wouldn't have been possible to stick to their usual wise-ass, witty ways as their city continued to recover from the biggest tragedy of their lifetimes. "At the time, our usual stupid s--- wasn't that funny," Horovitz told New York magazine.

"'To The 5 Boroughs' is misunderstood, in a way," he continues. "That was supposed to be our serious political album." It was also first and foremost a love letter to the city where all three Beastie Boys -- Horovitz, Diamond and Adam 'MCA' Yauch -- grew up. Just two days after the attack, the group visited MTV to talk about what they saw.

"I'm not far from the World Trade Center," revealed Diamond. "So I actually watched a lot of what happened, and it was really just a lot of disbelief for me... I still feel like I'm dealing with this much (holds fingers close together) of it."

Watch the Beastie Boys Talk About the 9/11 Attacks on MTV

Even in that state of shock, the group found time to accentuate the positive, praising New Yorkers for their reaction to the disaster. "One of the things that I think is amazing that I've seen here... is just how much people are actually really trying to help," Diamond said. "It's not like a scene of looting and 'what can I do for myself?,' it's like, 'how can I help?'"

Three years later, that same pride was evident on the 'To the 5 Boroughs' track 'An Open Letter To NYC.' Yauch begins with a rhymed blessing.

"Dear New York I hope you're doing well / I know a lot has happened and you've been through hell," he raps, adding, "Brownstone, water towers, trees, skyscrapers / Writers, prize fighters and Wall Street Traders / We come together on the subway cars / Diversity unified, whoever you are."

Watch the Beastie Boys Perform 'An Open Letter to NYC'

While the Beastie Boys had long ago moved away from the party-hardy subject matter of early singles like '(You Gotta) Fight For Your Right (to Party)' and 'No Sleep Till Brooklyn' in favor of deeper, socially and spiritually enlightened lyrical content, the overt political references of several 'To the 5 Boroughs' songs was still a bit surprising.

On 'Time to Build' they rapped of the perceived illegitimacy of President George W. Bush's first term in office and his refusal to think ahead ("We've got a president we didn't elect / The Kyoto treaty he decided to neglect," raps Yauch). With 'Right Right Now Now' they addressed the thorny issue of gun control in the shadows of the Columbine School shootings  ("Columbine bowling, childhood stolen / We need a bit more gun controlling").

Actually, the Beastie Boys didn't even wait for the album to come out to let people know what was on their minds. Soon after they began the recording sessions for '5 Boroughs,' they issued a free download entitled 'World Gone Mad' that took several shots at the Bush administration.

"We all got to a point where we felt like, we’re in this room in New York, we’re looking at each other every day, and we really felt compelled to speak our minds on what exactly we see happening right now," Diamond told MTV News.

They went even further on another non-album cut, accusing then-president George Bush of "acting mad s----y," tapping telephones and using the war in Iraq to increase his personal oil business profits on the internet-available 'This Government Needs a Tune Up.'

Hear The Beastie Boys Perform 'This Government Needs a Tune Up'

However, the whole album wasn't devoted to political commentary. The group also seemingly found comfort by dialing back their typical "everything including the kitchen sink" production style in favor of a stripped-down sound reminiscent of hip-hop's early days. As people often do in a time of crisis, they also surrounded themselves with friends and peers, using vocal samples from fellow New York rap legends such as Chuck D and LL Cool J for the hooks of songs like 'Rhyme the Rhyme Well' and '3 the Hard Way,' respectively.

The trio even went so far as to use a slightly re-arranged version of the Sugarhill Gang's pioneering 1979 anthem 'Rapper's Delight' as the basis for the single 'Triple Trouble.'

The album cover offered further tribute to New York City, featuring artist Matteo Pericoli's hand-drawn 22-foot long 'Manhattan Unfurled' -- complete with the twin towers of the World Trade Center still standing tall.

"They said it was one of the most heartfelt dedications to the city, and [that they] would love to use it for the cover," Pericoli told Juxtapoz. "When the goal is simple and shared there is not much to talk about."

Although 'To the 5 Boroughs' went platinum within a month of its release, it faded from the charts and public consciousness much faster than the group's previous albums. In effect, this marked the end of one of hip-hop's most amazing creative and commercial hot streaks -- which, if you can forgive the fact that it took people a few years to come around on 1989's landmark 'Paul's Boutique,' stretched all the way back to their debut album, 1986's 'Licensed to Ill.'

It was another seven years before the group released their next -- and sadly, final album, 2011's more lighthearted 'Hot Sauce Committee Part Two.'

Just over a year later, Yauch passed away after a three year battle with cancer. The surviving members of the group recently re-affirmed their decision not to make any more records without him.

More From TheBoombox