"Dhyána means to direct the mind towards the Supreme One. Remembering Parama Puruśa is dhyána. In this thought process there is a sense of mobility. The absence of mobility leads to crudeness and ultimate destruction. Those of you who are students of psychology will understand this subject better.
There are two distinct paths. The first is to stop the extroversial tendencies of mind and become absorbed in the inner goal; the second is to keep all the sense organs engaged in the same activity, such as kiirtana. When kiirtana was first invented, the psycho-philosophy behind it was this: at the time of kiirtana, the vocal cord sings, the ears hear, and the hands and feet dance,and thus all the organs are kept preoccupied with the divine. They are not allowed to move wherever they want but are kept engaged. There is a popular Indian superstition that when ghosts are not kept busy they break the necks of their prey. Similarly, if the sensory and motor organs are not kept engaged in the attainment of the divine, they may lead one astray. Kiirtana is therefore most beneficial as it keeps all the organs fully engaged in a spiritual pursuit."
Ánanda Vacanámrtam Part 8