Clue: Spiritual number is put in hands of six-footer as source of music (7)
Answer: PIANIST
Explanation: Spiritual number is put in hands of six-footer as source of music (7)
**PI** ("spiritual" or "number", or "spritual number"?) + **IS** in **ANT** ("six-footer") 
*I'm not 100% sure on this parsing, as I can't decide if Sleuth has used a cryptic clue within a crytic clue.