As observant pop fans have no doubt noticed, over the last few days, new songs have been released by two of the biggest acts of the early 21st century, Destiny's Child and Justin Timberlake. DC's "Nuclear," planned as the sole new track on the group's upcoming Love Songs compilation, debuted with an unexpected premiere on tech site Mashable last Friday, while JT's "Suit and Tie," to be the lead single off third album The 20/20 Experience, received a midnight release Sunday night on iTunes, ensuring a week of maximum digital sales.

It's virtually impossible not to draw comparison between the two songs, both because their rollouts were all but identical—both were announced for the first last week and came out just a few days later, with virtually non-existent hype for both rapidly ballooning into breathless anticipation—and because neither artist had released music in a number of years. We last heard from Destiny's Child with 2004's Destiny Fulfilled, while Timberlake's most recent LP was 2006's FutureSex/LoveSounds. In many ways, we thought we might not even hear from either artist again, with DC showing reluctance to reunite and JT showing reluctance to do just about anything involved with music, so to hear out of the blue that both had music on the way (and so soon!) was particularly exciting.

Now, for better or worse, the songs are linked in another way—the muted, underwhelmed reception both have received from expectant pop fans and critics. Upon its debut on Friday, "Nuclear" was met mostly with confusion and blankness, the song's understated, early-'90s retro groove and intimate, hushed vocals being a far cry from the Big Comeback Single most had expected. "For all the hoopla surrounding the song, it’s an oddly low-impact piece of music," bemoaned Stereogum, while fans expressed their disappointment over Twitter, and "Nuclear bomb" became a popular quip about the song.

With the release of Timberlake's "Suit and Tie" last night, the reception was similar, albeit a little differently framed—people seemed to like it, but appeared disappointed that they only liked it, without the song blowing them away or setting a new standard for pop music in 2013. "I'll probably never forget the moment I heard 'SexyBack'," testifies Jason Lipshutz of Billboard of JT's last comeback single, asking "In six and a half years, will you remember where you were the first time you heard 'Suit and Tie'?" Meanwhile, SPIN's Impulsive Review roundup sees each of its staffers awarding the song between a 5 and 7 out of 10, with Brandon Soderberg saying the "first Timberlake song in six years shouldn't be a slow-to-reveal-itself kind of sort of grower, now should it?" and Marc Hogan saying simply, "Ain't nobody disappoint you like Timberlake disappoints you."

Tough stuff for both singles, but to a certain extent, this is the hole that both artists have dug themselves into with their career paths. When your favorite singer or group goes off the grid for a half-decade or longer, you still kind of expect that they're continuing to evolve musically over that timespan, and that a new single or album won't pick up near where the artist left off, but will pack six or seven years' worth of musical progress into that first piece of comeback music, as if they'd been steadily recording in secret the whole time. In a way, it's even more exciting, because it's like you get to skip a transition level with the artist, as if that rookie playing for your favorite sports team just became a seven-year vet, without you having to watch him struggle through those years of growing pains in between.

What's more, JT and DC heap on their comeback expectations by having executed the Big Comeback Single once already. The previously mentioned "SexyBack" was an instant smash, beloved by virtually all, and redefined not only Timberlake's sound but the sound of pop music in 2006. The reception for Destiny Fulfilled's lead single "Lose My Breath" in 2004 wasn't quite as resounding, but it was still an exciting song that proved that the trio could move beyond the Darkchild-and-Shek'spere-helmed sound that defined them (and pop in general) at the turn of the century, and showed that Beyoncé's solo success hadn't dulled their imapct as a group. But both these comebacks came much earlier in the respective artists' careers, and after a much briefer absence. To expect similar comebacks once both artists had moved into their '30s, and pop had moved on to a new chapter without them, would be extremely unfair.

Needless to say, it doesn't always work out like that. Some artists come back after a long lay-off and decide that what they were doing the first time around should still serve them well enough. Some of them come back and decide "Hey, what's that new sound that's big on the charts / in the underground these days? Yeah, let's give that a shot this time." And some of them come back and figure that their long break has given them a clean slate, and now they can do whatever the hell they want with their music without having to answer to any kind of fan expectation.

With DC and JT's respective comebacks, it seems more like that third type than anything else. "Nuclear" belies Beyoncé's comments about how she's been trying to get back to the feel of '90s R&B, and though the song's sound is more of the forgotten, pre-Boyz II Men part of the decade in R&B, it still packs a strong memory of groups like Seduction and Linear, and a time when pop, freestyle, new jack swing and traditional R&B were all getting mixed together in big hit pop songs. It's also in line sonically with what a lot of underground pop groups like Lemonade and Shine 2009 have been doing recently, in reviving this kind of forgotten period of pop history, which occurred when the Destiny's Child girls were all just entering their teens, their formative musical years.

With Timberlake, who's already talked a whole lot about how his new album will be the sound of him "creating with no rules and/or end goal in mind and really enjoying the process," "Suit and Tie" sounds like him and Timbaland getting loose in the studio, and ending up crafting something close to the perfect 21st century wedding song–appropriate enough, considering JT got married late last year. Though sonically, the song obviously has some similarity with Timberlake and Timbaland's mid-'00s collabs, the feel is actually much closer to something off the last R. Kelly album, where Robert also cut bait with trying to keep up with modern trends and decided to make feel-good, middle-aged dance music. It's not really retro or futuristic, it's just kind of out-of-step.

The two songs are really quite good, and should probably be commended for the respective artists' doing what they feel like doing, not kowtowing to modern trends or making a self-conscious Big Comeback Single just for the sake of doing so. In fact, some have already come around to acknowledge this, as Idolator's recent roundup of "Nuclear" reviews will testify, and "Suit and Tie" is off to a resounding start commercially, topping the iTunes chart quickly after its release last night, and likely on its way to a big Hot 100 debut next week.

But the sense of unrealized expectation surrounding both is still pervasive, which while inevitable due to the stature and extended absence of the two artists, is still a pretty big shame, and proof of just how slim the margin of understanding among fans and critics becomes when you go so long without putting out anything for consumption. Imagine if you heard "Nuclear" for the first-time just as the compilation bonus-track that it is, or "Suit & Tie" as the intro track to Timberlake's latest album, not some kind of big statement of intent, but just the first look into where he's at now in 2013, personally and musically. We tend to think the headlines would be more about JT and DC releasing great new pop music, and less about how they failed to deliver on expectations no artist should ever really have to face.