Depends on the precise moment the question is asked; currently it's Blondie's Heart of Glass, segue-ing into Tony Rice & David Grisman, then the Tubes, the Cardigans, the Beatles, Taj Mahal
My current Mondo Playlist contains more than 650 selections, ranging from Classical to Bluegrass, Rock, Country, Acapella, and many artsts who are difficult to classify in a single genre.
It's about a day and a half's worth of music, set to shuffle and continuously loop. Lots of Beatles, Police, James Taylor, Shawn Colvin, Sheryl Crow, Who, Weird Al, Warren Zevon, Ry Cooder, Dixie Chicks, Don Henley, Diana Krall, Elvis Costello, Dave Brubeck, Chuck Berry, Delbert McClinton, Frank Zappa, James McMurtry, Jimi Hendrix, Bette Midler, Bela Fleck, Prokofiev, Mussorgsky, etc., et.al.