Rush to eye keyboard instrument (4,5)
I believe the answer is:
reed organ
'keyboard instrument' is the definition.
(I've seen this before)
'rush to eye' is the wordplay.
'rush' becomes 'reed' (I've seen this in another clue).
'to eye' becomes 'organ' (I can't justify this - if you can you should give a lot more credence to this answer).
'reed'+'organ'='REED-ORGAN'
Can you help me to learn more?
(Other definitions for reed organ that I've seen before include "Melody Maker?" , "small instrument" , "supports traditional services" , "What you might hear" , "Keyboard instrument, harmonium" .)