"elv1s: 30 #1 hits" was compiled by ernst mikael jorgensen and roger semon using chart data from the pop singles charts in "billboard", "cashbox", "new musical express", and "record retailer". not all of elvis' number ones are included as it is only a one-disc set. it was part of a massive campaign by rca and bmg to celebrate elvis in the 25th anniversary of his death.