CDJs XDJs load lock when ON AIR
CDJs and XDJs has 2 modes of LOCK LOAD: LOCK and UNLOCK. Add 3rd mode - LOCK WHEN ON AIR. This mode will allow loading a new track into the deck when the track is playing, but will prohibit loading if this deck is playing on air.
DJs don't have to stop the track that they have already played to load a new one. It’s enough that the fader is down. At the same time, if the CDJ is on air and it plays, then the new track cannot be loaded.