You want to know where rock is? Rock is not dead, nor is it a thing of the past.

Rock is very much alive, and the Foo Fighters are proof.

On Feb. 21, the Foo Fighters brought the house down at the Wachovia Spectrum (not literally of course, that’s for a little later) and left the city of Philadelphia on its knees.

Dave Grohl and company looked as confident as ever as they took the stage to one of the most intense Foo songs to date, “Let It Die.”

From then on, it was nothing but constant energy and flawless showmanship, as the Foo ripped through a blazing two-and-a-half-hour set of classics as well as some newcomers from their most recent album “Echoes, Silence, Patience, and Grace.”

During “Times Like These” and the show-stopping rocker “All My Life,” Grohl was all over the stage, running up and down the catwalk like a madman and getting the crowd in a frenzy.

Grohl’s sense of humor even added an extra element to the show, making it more enjoyable as the night went on.

“Remember the first time we played in Philadelphia and played for only an hour?” Grohl bantered to the crowd. “Well, you know what I want to do this time: play for six-and-a-half hours!”

This drew a huge roar from the crowd.

Although the Foo couldn’t keep its promise of a six-and-a-half-hour show, its nearly three-hour set was nevertheless impressive.

The concert was filled with the classic sing-alongs like “Monkey Wrench,” “Breakout” and “Learn to Fly,” as well as a heartfelt rendition of “Everlong,” which kept the audience entertained and the Foo Fighters at the top of their game.

Oh yeah, and did I mention that Grohl and fellow guitarist Chris Shiflett can play the heck out of the guitar?

The two became entwined in a guitar battle, each channeling Jimmy Page in the process.

Even dummer extraordinaire Taylor Hawkins joined in on the fun, jamming out a monstrous drum solo.

As much as they rocked hard, the Foo Fighters showed their softer side with a five-song acoustic set as a floating stage came down from the ceiling, as if the rock gods were lowering it themselves.

The quartet turned into an octet as more musicians came to play the accordion, violin and even the triangle, which then led to what was quite possibly the only triangle solo at a rock concert ever.

During the acoustic set, the Foo Fighters performed a beautiful version of “My Hero,” which seemed to be a fitting tribute to Kurt Cobain. Hawkins got to take the spotlight as well, singing and playing drums to “Cold Day in the Sun.”

Ever since their debut in 1995, the Foo Fighters have been the most consistent band in rock.

They have produced numerous Grammy Award-winning albums, and they are just getting started.

As the night drew to a close, Grohl mentioned that the Wachovia Spectrum was going to be torn down, which he seemed to be legitimately disheartened about.

“I think they should wait until we play 53 shows in a row here,” Grohl said, referring to the Grateful Dead’s 53 sold-out shows at the Spectrum.

So in what may possibly have been the last Foo Fighters song performed at the Spectrum, Grohl and co. brought the night to an emotional end with “Best of You,” which has the crowd screaming at the top of their lungs and wanting more.

What was witnessed at this concert was a confident Foo Fighters band, fresh off a Grammy win and still seeking new creative directions. Their influence on music today cannot be ignored.

The Spectrum has seen the likes of legends such as Paul McCartney and Jerry Garcia, as well as countless other musicians, but another name has just been added on that list: Dave Grohl.