To learn the tango takes courage! (5)
I believe the answer is:
heart
'courage' is the definition.
(heart is a kind of courage)
'to learn the tango' is the wordplay.
'to learn' becomes 'hear' ('hear' can be a synonym of 'learn').
'the tango' becomes 't' (phonetic alphabet: alpha, bravo, charlie etc.).
'hear'+'t'='HEART'
'takes' acts as a link.
(Other definitions for heart that I've seen before include "show enthusiasm" , "one needs to beat" , "Cardiac courage" , "Vital part" , "Centre; valour" .)