This pop/rock/neo-soul group had success early, scoring a record deal as high schoolers. Then known as Kara's Flowers, they also experienced failure early, getting dropped by their label. But after a brief go at college, they reformed as Maroon 5 to big success. After their second album debuted at No. 1 in 2007, singer Adam Levine told Rolling Stone the band was already reaching its peak. "If this record does as well as we think it will, maybe we'll do one more and split."
In their favor: They've had two more albums since then.
Biggest threat: The final part of that quote: "I don't want to overstay our welcome."