The mid-'90s, when top 40 began its comeback, were dotted with hits from acts that just a few years earlier would have had trouble getting past triple A radio-Melissa Etheridge, Shawn Colvin, Dogs Eye View. But even when modern AC exploded, there was no restitution made to those artists who had been making similar, equally appealing records a few years earlier. Mary Chapin Carpenter, who had ended up country only because modern AC didn't exist in 1989, never became a pop artist. "Here's Where the Story Ends" by the Sundays may have anticipated the sound of modern AC, but it never got played there.

Mid-'90s modern AC and top 40 couldn't go back for the records they missed, in part, because there was so much new product coming out in a similar vein. Top 40 has stunned the world by accommodating the Lumineers and Ed Sheeran. But there's already a queue of recent indie and/or alternative hits. And at this moment, it seems like anything goes. Could the Black Keys' "Little Black Submarines" go to pop? Nine months ago, it barely seemed to belong at alternative.

So it's unlikely that either labels or PDs will seek out those songs that top 40 missed during the past few years. But they undoubtedly exist. Some got as far as Adult Top 40 but never seemed like Mainstream candidates. Others were hits all over the world, but would have been tough sells for top 40 at the time. Now, they wouldn't even be the most eclectic songs on the radio. And some, like Lana Del Rey's "Video Games," were probably no more than a month or two ahead of their time. And, no, not all of them actually have banjo, but they're all quirky pop of some sort.

Florence & the Machine, "Dog Days Are Over": If you're an adult top 40 programmer, it did cross to pop, of course. With the combination of hot AC, alternative and various synchs, it's already as big as a song can be without top 40 airplay-something I've seen borne out in music testing recently.

MGMT, "Electric Feel": A top 40 smash in various places around the world, it wasn't even a big alternative hit here. And given MGMT's effective decision to alienate alternative radio on its next album, it probably had no interest in going to top 40 with this song.

Brooke Fraser, "Something in the Water": A Down Under hit that spread across Europe during the following year, the best it could manage here was an indie label release to noncommercial triple A. Now, Phillip Phillips' "Home" has already made the "tent revival" feeling of Fraser's hit familiar at radio.

The Naked & Famous, "Young Blood": If its successful run at alternative had happened about four months later, it would either have crossed to top 40 or perhaps be in the queue now (like AWOLNATION's "Sail"). Its pop potential is borne out by 3,000 spins to date at modern-leaning AC KLCK (Click FM) Seattle.

Fitz & the Tantrums, "Money Grabber"; Aloe Blacc, "I Need A Dollar": Before "Rolling in the Deep," it seemed like the Amy Winehouse/Duffy formula of '60s soul and today's snarkiness had fulfilled its quota twice over. Now, it's a river running soul deep. Fitz is already warmed up by Hot AC here. "I Need a Dollar" has U.S. synchs, plus an international track record.

Ray LaMontagne, "Trouble" : It showed up pretty quickly on "American Idol," back when that show, pre-"Glee," was the indicator of how quickly a non-radio song had infiltrated the mainstream. Since then, both song and artist have maintained a place on triple A. And if you played it after "The A Team," you'd actually be picking up the tempo.

Empire of the Sun, "Walking on a Dream": Time and musical trends had to catch up with "Trouble." "Walking" would have sounded just fine on the radio in 2009 when it was (yes, you guessed it) a top 40 hit worldwide. Never on top 40's radar, this was one of those records that your kids seemed to know somehow.

Muse, "Undisclosed Desires" : It went to Hot AC, but never picked up enough top spin for top 40. If top 40 finally acknowledges Muse with "Madness" (and so far, PDs are taking their time), this would still sound great.

Tegan & Sara, "Walking With A Ghost": In 2004, it was still a little to the left of even Alternative's more true.alt stations. Even then, however, it still had the feel of a hit record--the repetition, the power-chords--and a 2:30 running time. It just wasn't living in the right neighborhood. Now the duo regularly have Canadian hits, both by themselves and in collaboration with dance DJ/producers.

To this list, reader and frequent contributor Thomas Smith also adds Edward Sharpe & the Magnetic Zeros' "Home," One eskimO's "Kandi," "Falling Slowly" from "Once," and Old Crow Medicine Show's "Wagon Wheel"-the latter successfully brought to country by Darius Rucker. So, what's your list? Email me ( sean.ross@billboard.com).