Bhojana is for the development of the body so is bhajan for the development of the soul.
Nadopasana and Shabdo-pasana washes the mind of fears and evil thoughts and fill the mind with peace and tranquillity.
There is an intimate relationship between music and God. But this relationship is established only when Nadha is approached with reverence and devotion. Nadhopasana leads to moksha.
There are four types of mind. The mind which opposes Dharma is lifeless; a sinful mind is sick; a greedy mind is lazy but the mind immersed in Bhajan - Keertan is indeed healthy.
It was Ramanam Japa that raised Valmiki into Maha Rishi. So do nama Sankirtan with gusto and attain eternal bliss.
Bhakti and nama Sankirtan generally go together. All music has evolved out of OM, the mystic syllable which symbolises the Absolute. To worship God through music called is Nadopasana.
The body is not permanent, it is not pure. Keep the body pure by taking satvic food. Discipline the mind by chanting the sacred hymns.
Since all cannot do tapas (austerities) the easiest and most universally acceptable form is namasankeertana. It opens the door to the province of bakthi as the songs are dedicated to the glorification of Lord.
Human birth is meant for singing the nama-sankeertana with pure mind and a sincere heart.
No outward show is needed to please God.