Step 1: Understanding the Concept:
The question asks to identify the teacher (Guru) of Raja Chhatrapati Singh, a famous patron and exponent of Pakhawaj.
Step 2: Detailed Explanation:
Raja Chhatrapati Singh of Bijna was a celebrated Pakhawaj player from a royal family in Uttar Pradesh. He was a prominent disciple of the legendary Pakhawaj maestro of the Kudau Singh tradition, Guru Purushottam Das. This lineage is known for its complex and powerful style of Pakhawaj playing.
Step 3: Final Answer:
The Guru of Raja Chhatrapati Singh was Guru Purushottam Das.