Fellowshipping with the HolySpirit and meditating on His Word is how we worship Him. He wants us -> to know Him, -> to draw near to Him, -> to recognize that we are one with Him, -> to praise Him with our words -> to sing to Him, -> to shout His glory.
Spiritual songs are songs with melodies that are uplifting with lyrics that echo the WordOfTheLord and His Grace and goodness.