Alison Krauss, Willie Nelson, Blue Highway and Lee Greenwood make guest appearances on polka king Jimmy Sturr's upcoming album, Rock 'n' Polka. Set for Sept. 14 release on Rounder Records, the album includes polka versions of rock classics such as Elvis Presley's "Don't Be Cruel" and the Beach Boys' "Fun Fun Fun." ... Alt.country artist Neko Case has recorded a cover version of Loretta Lynn's "Rated X" for The Tigers Have Spoken, a live album to be released Nov. 9 on Anti Records. Recorded at concerts in Chicago and Toronto, just two of Case's originals are among the album's 11 tracks. The remaining tracks are covers of songs popularized by Buffy Saint Marie and the Shangri-Las, among others.