try hanging around in either the Hull Breach or the Mausoleum for the "enemy moves against each other" event. When it does occur - go to one of the doors where they spawn in and super on them in the door when they spawn in. Things like Sunbreaker or Nightstalker work the best. Then kill, kill, kill. till you start getting the majors. It might be better to try and let them get out the door - as I think there's a "stop" on drops when you kill them in their spawn. Another guaranteed drop of either is from someone else firing up the command beacon. Get hits and/or the kill on the champion. If you don't see a white engram (not the triangle, but an engram lookign thingy) on the ground - leave the area and come back. I usually run off to Dantallion (through the ship) and turn around and come back as soon as I hit the top of the ramp. FYI - you can hold a command beacon key and a skyburner at the same time - holding either will not prevent you from getting the other. You cannot hold more than one of each though. I've noticed the drops for wormsinger and command are very low when your out in the world killing stuff. The only places I've ever seen them are from majors or ultras. Even then, a load of majors will rarely drop one. When the strike brothers was the nightfall though - I filled up on both and couldn't pick up any more. Hope this helps.