Send tenor memo about time-keeper (9)
I believe the answer is:
metronome
'time-keeper' is the definition.
I can't tell whether this defines the answer.
'send tenor memo' is the wordplay.
'send' indicates anagramming the letters (I've seen 'sending' mean this (letters are sent to different positions)).
'tenor'+'memo'='tenormemo'
'tenormemo' with letters rearranged gives 'METRONOME'.
'about' acts as a link.
Can you help me to learn more?
(Other definitions for metronome that I've seen before include "Device for keeping time" , "Device to indicate tempo" , "Pendulum to indicate tempo of music" , "Device to help regulate tempo" , "Ticker setting tempo of music" .)