On his 1999 LP Eletro Ben Dodô, Lucas Santtana updated Seventies tropicalia rock, sampling Caetano Veloso behind what appears to be reimagined Tom Zé album art. Sem Nostalgia also goes back to the future, using just acoustic guitar and voice to make an utterly modern LP. On "Cira, Regina e Nana," digital technology turns a whop on a guitar into the sound of an electric typewriter; on "Super Violão Mashup," plucked strings conjure something resembling an Afrika Bambaataa electro-funk jam. Like Feist and Tune-Yards, Santtana erases the line between acoustic and electronic music, waxing nostalgic without the nostalgia.

Listen to "Super Violão Mashup":

“The A Team”

This debut track from the then-20-year-old British singer-songwriter has a dark story behind it. Sheeran says he culls songwriting inspiration from "viewing other people's situations," which, for the heroine in "The A Team," involves drug addiction and prostitution that began as a teen. Sheeran paints the woman's trials with haunting imagery such as "But lately her face seems/Slowly sinking, wasting/Crumbling like pastries." "I did a gig at a homeless shelter, [and the song] is about one of the women there. It's her story," he said.