Crossword Genius

Given this, one must hit the right note — it's essential to get on (8)

Ross

I believe the answer is:

keyboard

'given this one must hit the right note' is the definition.
(percussion instrument)

'essential to get on' is the wordplay.
'essential' becomes 'key' (I've seen this before).
'to get on' becomes 'board' ('board' can be a synonym of 'get on').
'key'+'board'='KEYBOARD'

'it's' acts as a link.

(Other definitions for keyboard that I've seen before include "It can produce notes" , "Data entry device" , "Piano or computer device" , "one lays hands on" , "Component of piano" .)

I've seen this clue in The Times.
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