Folk-rocker Dan Bern is among the latest. His new CD has eight politically charged tunes that swing between "President," a silly Woody Guthrie/Bob Dylan/Arlo Guthrie-style talking blues number about what Bern would do as commander in chief (John McEnroe a cabinet member?), to the sobering first-person account from a disabled veteran in "After the Parade." The signature number is the closing sing-along "Bush Must Be Defeated." Musical anti-Bush screeds might be as common as blow-up Scooby Doo dolls at the state fair, but as long as those fed up with business in Washington do not appear to tire of them, there will be room for more.