Staff members who contacted the Herald were aghast at plans for a playlist, which they feared might restrict content to modern music.
But RNZ chief executive Paul Thompson said the change was about delivery mechanism and not content.
The broadcaster was replacing an archaic system where occasional music was stored on compact discs, he said.
National Radio was not about to become a rock station, Thompson said.
There was some minor tweaking of the Radio New Zealand National music playlist in progress with the aim of having between 2,000 and 3,000 songs in the National rotate ready for use in the playout system.
The new playlist applies to Radio New Zealand National 'rotate music' only, said spokesman John Barr.
"Rotate music is most often heard in the overnight programme and the change doesn't affect the ability of music and specialist programmes to select tracks.
"It does not mean that people like Phil O'Brien can't play the quirky stuff so popular on Matinee Idle," he said.