In the '90s, singer-guitarist Mike Doughty fronted Soul Coughing, an N.Y.C. ensemble that inventively combined jazz, hip-hop, indie-rock, and quasi-beat-poetry lyricism. He did a whole bunch of heroin too. Then he got clean, quit Soul Coughing, and pursued a solo singer-songwriter career, happily nurturing his inner Dave Matthews. In fact, he's become a pal, collaborator, and frequent touring partner of Matthews. You might even mistake the voice and loose-limbed, jazzy pop grooves on Doughty's new album, Golden Delicious, for Matthews'. Wanna know how Doughty feels about the comparisons? You can ask him yourself: At recent shows, he's invited fans to drop queries into a question jar. Between tunes, he answers them. And like the music he's made over the years, nothing's off-limits.