Train, 'Hey Soul Sister' (Sessions)

After 2006's 'For Me, It's You,' Train had run off the rails. Despite more than a decade of hits like 'Drops of Jupiter,' 'Calling All Angels' and 'Meet Virginia,' the band's three core members, Pat Monahan, Jimmy Stafford and Scott Underwood, were feeling burnt out and more than a little tired of each other. They parted ways with their future as a band very uncertain.

But after spending three years apart, the trio realized they weren't done with each other quite yet. They reconvened for 'Save Me, San Francisco,' recorded primarily in London with producer Martin Terefe (Jason Mraz, KT Tunstall), with a new, joyous attitude. Not only did they return, they rebounded stronger than ever with the care-free, upbeat 'Hey Soul Sister,' the group's biggest hit in its 15-year history.

At a recent AOL Sessions taping, the band talked about falling in love, Justin Bieber, and its glorious second act.