Pop star Elvis Costello will emcee Wednesday's (June 13) Carnegie Hall concert featuring the musical cast of O Brother, Where Art Thou? Costello is stepping in for John Hartford, who died June 4 of cancer. Hartford appears on the million-selling soundtrack and hosted the first O Brother concert in May 2000 at Nashville's Ryman Auditorium. Alison Krauss and Union Station, Emmylou Harris, Ralph Stanley, Norman Blake, The Cox Family, The Fairfield Four, Chris Thomas King, The Whites and The Peasall Sisters are among those who will perform at New York City's most celebrated auditorium. Costello recorded a number of country songs in Nashville for his 1981 album, Almost Blue, and has worked with the Fairfield Four in the studio and on stage.06/11/01