Which practice is essential in attaining the objectives of Raja yoga?

Concentration as a meditation technique is fundamental in attaining the objectives of Raja yoga because Raja yoga, often referred to as the "Royal Path," emphasizes the importance of mental control and focus. The core aim of Raja yoga is to still the mind and achieve a state of deep meditation, wherein the practitioner can connect with their true self and experience higher states of consciousness.

Raja yoga integrates various practices, with concentration serving as a pivotal element that facilitates the meditation process. Without the ability to concentrate, one may struggle to quiet the incessant fluctuations of the mind, making it difficult to delve into deeper meditative states. Regular practice of concentration techniques helps in the development of inner discipline and mental clarity, which are essential for progressing on the path of self-realization and enlightenment.

Other practices mentioned, such as yoga nidra, devotional singing, and physical exercises, while beneficial in their own right, do not directly address the central goal of mental focus and stillness that Raja yoga prioritizes. Each of these practices can complement Raja yoga, but concentration specifically aligns with the meditative and mental mastery objectives that define this yogic path.