First you need to have these rods and locations unlocked :

----- rods -----

Thalassar's Ruin

seraphic rod

lost rod

celestial rod

lucid rod

Rod Of The Forgotten Fang

Pinion's Aria

rainbow rod

one of these Duskwire or Polaris Serenade or Astraeus Serenade

and x1 moonstone

----- Locations -----

Atlantis (Sunken Depths Pool)

The Depths

Above The Clouds

Hades' Underworld of Indefinite

Mineshaft

Zeus's Thunder of Chaos

Luminescent Cavern and Crimson Cavern.

Atlantis kraken pool

calm zone

what you will get :

Lullaby fully unlocked with 5 modes