The Girl in the Other Room reveals two new things about Diana Krall. One: that her interpretive repertoire is expanding. Two: that, in collaboration with her husband, Elvis Costello, Krall has discovered her inner singer-songwriter. Both directions signal good news. Where Krall had built a career by delving deeply into the work of the classic Great American Songbook composers of the '30s, '40s, and '50s, she’s now setting her sights on more contemporary figures, including Mose Allison (“Stop This World”), Tom Waits (“Temptation”), Chris Smither (“Love Me like a Man”), Joni Mitchell (“Black Crow”), and Costello (“Almost Blue”) -- although, in truth, the most recent of these tunes, “Temptation,” is nearly 20 years old. To her credit, Krall injects as much individuality into these reinterpretations -- her blues singing has become noticeably confident and assured -- as she did on the work of more hallowed composers. “I’m Pulling Through,” made famous by Billie Holiday and given a quality reading by Krall, is the album’s only standard. The six original tunes reveal a more personal approach. With Krall handling the music and Costello adding his input to the lyrics, the two work up songs that share an unexpected but winning blend of Joni Mitchell’s unconventional melodicism and Costello’s sharp and literate lyrical concerns. The obviously personal nature of the work -- the theme of change, its difficulties and potentials, pervades these songs -- allows us a closer look at an artist whose cool approach to her material has often kept her audience at arm’s length. Obviously influenced by her husband's artistry as both a composer and vocalist, Krall’s phrasing on the new tunes at times reflects Costello’s inimitable delivery, but Krall has nonetheless found her own distinct voice as a singer-songwriter. With The Girl in the Other Room she gives notice that the future promises pleasant surprises.