Elvis Costello has been touring with Bob Dylan since late September, opening the shows as a solo performer before giving way to Dylan and his sextet. Last night in St. Louis marked the first and what many hope will not be the last on-stage collaboration between the two artists. Following a fourteen song set from Dylan and his band at the Fox Theatre, Costello and Dylan emerged bearing acoustic guitars to perform ‘Tears Of Rage’ as a duo (the song written by Dylan and the Band’s Richard Manuel, first appeared on the Basement Tapes). Dylan’s full band then returned for a second encore of ‘Thunder On The Mountain’ and ‘All Along The Watchtower.’ With any luck Costello and Dylan will do it again, perhaps on Wednesday in Iowa City, IA.