Singer-songwriter Dar Williams [ tickets ]--who has built a strong grassroots following over the last decade via extensive touring on the coffehouse and college circuits--returns to the road in April to back her sixth album, "The Beauty of the Rain."

The new album, which just hit stores, features a long list of well-known guests: Alison Krauss on vocals, Bela Fleck on banjo, John Popper on the harmonica and backup vocals, Stefan Lessard (of Dave Matthews Band) on bass, John Medeski on keyboards, Chris Botti on trumpet, Cliff Eberhardt on vocals and Michael Kang (String Cheese Incident) on fiddle.

"It can be a little lonely sometimes being a girl with a guitar," Williams said in her record company biography. "I wanted to reach out into the world and see what else was going on."

Williams, whose style has drawn comparisons to folk-music greats like Joni Mitchell and Joan Baez, has sold more than 500,000 albums over the course of her career, according to Razor & Tie. Her upcoming tour will visit a mix of colleges, theaters and clubs.