It’s tough enough for a song to become a worldwide smash, but what about those songs that became hits without industry support? Or that weren’t even supposed to be singles in the first place? These nine songs managed to top the charts despite the odds.

1. "ERUPTION" // VAN HALEN

No song exemplifies Eddie Van Halen’s technical prowess and all-around musical genius like this one-and-a-half-minute instrumental. But the song wasn’t meant for public consumption when it was first recorded. Van Halen was simply warming up early one morning in the studio, and producer Ted Templeman decided to put the exercise on tape. The producer decided to include the recording as-is on the band’s 1978 self-titled debut—to the chagrin of the guitarist, who later said, "To this day, whenever I hear it, I always think, 'Man, I could’ve played it better.'" Fans don’t seem to agree: The track is consistently voted as one of the greatest guitar solos of all time.

2. "SWEET CHILD O' MINE" // GUNS N' ROSES

One of Guns n' Roses' most memorable riffs was also the result of a warm-up. While hanging out during preproduction for the band’s 1987 debut, Appetite for Destruction, Slash started noodling around with a string-skipping exercise. Axl Rose overheard the resulting riff, and the following day during rehearsal, he coaxed his reluctant guitarist into replaying the melody and started singing along. The final product stayed at No. 1 for two weeks in 1988.

3. "APPLAUSE" // LADY GAGA

Gaga wrote somewhere in the vicinity of 100 songs for her 2013 effort, ARTPOP, and claims this song almost missed the cut. It was Interscope Record head Jimmy Iovine who ID’d the track as the album’s first single, after hearing it during a listening session of 40 ARTPOP contenders. As usual for the record-biz veteran, his instincts were right: The song went all the way to No. 4.

4. "ANOTHER ONE BITES THE DUST" // QUEEN

Queen didn’t originally intend to release this sparse, groove-laden recording as a single. Drummer Roger Taylor even went so far as to say "That will never be a hit," of the cut off 1980’s The Game. It was Michael Jackson, visiting the band backstage after an L.A. show, who convinced the band otherwise. The King of Pop knew what he was talking about: The song went to No. 1 and remains Queen's best-selling single in the States.

5. "THRIFT SHOP" // MACKLEMORE & RYAN LEWIS

By all rights, this Grammy-winning hip-hop gem never should have been a single, let alone a No. 1 hit. The Seattle-based duo self-released their recording in August 2012, as the fourth single off their album The Heist. After six months of building a devoted following through touring and social media (and without any mainstream promotion), the song finally hit the top of the charts in February 2013.

6. "STAY (I MISSED YOU)" // LISA LOEB

Macklemore was the first label-less artist to go to No. 1 since 1994, when Lisa Loeb did the same thing with the lead-off single from the Reality Bites soundtrack. Were it not for the fact that she was friends and neighbors with the film’s star, Ethan Hawke, who pressed for the song’s inclusion on the soundtrack, the singer-songwriter might still be toiling in obscurity.

7. "LOSER" // BECK

When Beck recorded this song in 1991, he never intended it to be a Gen X anthem. Instead, he was merely trying out some raps to impress producer Karl Stephenson, at whose house he was recording at the time. Perhaps influenced by Stephenson’s hip-hop ties, the then-unknown singer, who did occasionally rap during his shows between songs, freestyled some lyrics in the spirit of Public Enemy. The song’s famous chorus—"I'm a loser, baby, so why don't you kill me"—was Beck’s response to hearing his attempt played back to him; as he later said, "When they played it back, I was like, 'I’m the worst rapper!'" Three years later, the song went into heavy rotation on radio and MTV, and those lyrics became the poster song for a new genre called "slacker rock."

8. "YOU AIN’T SEEN NOTHING YET" // BACHMAN TURNER OVERDRIVE

The lyrics to BTO’s 1974 No. 1 hit were as much a goof as those in "Loser." Randy Bachman, while producing BTO’s third album, Not Fragile, used the song as an instrumental to test out the equipment in the studio, perfecting the sound for the tracks actually intended for the record. The lyrics were something he’d sung off the cuff, stuttering as a gentle poke at his brother, who was known for having an actual stutter. But when Mercury Records head Charlie Fach heard the song while looking for the band's next single, he knew he’d found a hit and insisted they include it on the album. According to Bachman, the song appears—at Fach’s insistence—exactly as it was when they used it to test the studio, despite the guitars being out of tune!

9. "CHERRY PIE" // WARRANT

This 1990 hit also wouldn’t have existed if not for the label’s insistence—literally. Warrant were all set to hand over their second album to Columbia Records when label president Don Ienner called requesting another track. Ienner was looking for a massive hit—"another 'Love In An Elevator,'" according to Warrant singer Jani Lane—and hadn’t heard one on the record as it stood. Lane responded by writing "Cherry Pie" overnight. The song went to No. 1 and remains one of Warrant’s best-known contributions, but because of its history, it’s never sat well with the band. Lane even went so far as to tell VH1, "I could shoot myself in the f**king head for writing that song."