Study of cadences (3)

I believe the answer is:
den
'study' is the definition.
(den can mean an office or study)
'of cadences' is the wordplay.
'of' indicates a hidden word.
'DEN' can be found hidden inside 'cadences'.
(Other definitions for den that I've seen before include "Wild animal's lair" , "Private office" , "Gentleman's study or animal's lair" , "Animals' shelter" , "Home of the beast" .)