When Geoff Jones sings, he combines jazz and soul with a mellow baritone. Geoff performs a lot with guitarist Joh Della Selva, and the two bring their repertoire of great songs to Umbra in Minneapolis, this Friday night from 7 till 10. When Geoff talked to Phil Nusbaum, the talk turned to the staying power of standards such as Rodgers and Hart’s Where or When.