Harsh, quick ringing sound of first test with a new guitar (5)
I believe the answer is:
twang
'harsh quick ringing sound' is the definition.
'twang' can be an answer for 'sound' (twang is a kind of sound). I'm not sure about the 'harsh quick ringing' bit.
'first test with a new guitar' is the wordplay.
'first test' becomes 't' (nst letter of 'test').
'with' becomes 'w' (abbreviation).
'new guitar' becomes 'ng' (this could be a standard abbreviation I've not previously seen).
't'+'w'+'a'+'ng'='TWANG'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for twang that I've seen before include "A nasal intonation in speech, or sound of guitar" , "Pluck (a string)" , "Plucked string sound; nasal voice" , "Nasal quality - strumming noise" , "Nasal tone of voice" .)