It seems that the band Elway might have a good argument that there is no confusion, mostly because there is likely little evidence of actual confusion, the goods produced by John Elway and the band Elway are entirely different, and the marketing channels of the two parties probably do not overlap. Still, John Elway might have pretty damning evidence with regards to the band Elway's intention for picking the name and may be able to argue that the name "Elway" is a very strong mark.