Classic rock is about heavy hooks, power chords, and tight harmonies, but it’s also about letting loose and enjoying the good times — and there’s no better time than Friday evening, when we pick up our paycheck, punch out of work, and enjoy a couple days of much-needed rest and relaxation.

This Friday, we're paying tribute to one of the biggest (and most enduring) mid-period hits from the Rolling Stones. Originally released on 1978's 'Some Girls' LP, 'Beast of Burden' found the band at a crossroads, both in terms of current trends -- which had boxed their brand of rock in between disco and punk on the charts -- and in terms of lineup upheaval; the sessions for the record saw guitarist Ron Wood performing as a full member for the first time, while co-founder Keith Richards' long-term fate hung in the balance during a widely publicized trial for heroin possession.

All that turmoil might have sunk a lesser band, but with his back to the wall, frontman Mick Jagger doubled down to drive a vibrant, eclectic creative outburst at a time when the Stones needed it, drawing from the dominant sounds of the day without yielding too much of the band's signature sound. The result was a worldwide smash that climbed to the upper reaches of worldwide charts and was certified six-times platinum in the United States alone -- in addition to spawning a series of hit singles that included disco-derived leadoff cut 'Miss You' and its followup, 'Beast of Burden.'

According to the Stones fan site Time Is On Our Side, while 'Burden' was largely written by Jagger, the song started with Richards, who's quoted as saying, "All I did was throw out the phrase 'beast of burden' to Mick, and I played him the music, and then he took it off by himself and did a beautiful job on it."

And what's the significance of the title? According to Richards, it was a sweet (albeit sly) acknowledgement that his partner Jagger had been carrying the band while Richards was tied up with drug and legal problems. "I was trying to say sorry to Mick for passing on the weight of running this band," he explained in 2011. "We were at the stage where we were getting bigger. The whole music business was getting bigger, and I was basically trying to say to Mick: You don't have to do it on your own... At the time Mick was getting used to running the band. Charlie was just the drummer. I was just the other guitar player. I was trying to say, 'OK, I'm back, so let's share a bit more of this power, share the weight, brother.'"

As well as it works as an anthem of honest regret and brotherly love, 'Beast of Burden' is also a pretty terrific admission of intrinsic need -- and a defiant expression of strength -- which, along with its gently strutting beat and fluidly intertwining lead guitars, helped make the song a Top 10 U.S. hit in late 1978. It also boasts more than a few lines that go perfectly with that Friday evening drive out of the company parking lot, but why wait for 5 o'clock? Hit the 'play' button on the clip we've helpfully embedded below, turn up the volume, and let the weekend start now.

Rolling Stones, 'Beast of Burden' (live)

More From Ultimate Classic Rock