Greeting musical instrument that’s getting new start (5)
I believe the answer is:
hello
'greeting' is the definition.
(hello is a kind of greeting)
I cannot understand how the remainder of the clue works.
(Other definitions for hello that I've seen before include "Routine response to telephone call" , "A salutation" , "Musical with Satchmo and Streisand" , "royals dominate its pages?" , "Conversation starter" .)