Type of sax is key, by end of solo (4)
I believe the answer is:
alto
'type of sax' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'key by end of solo' is the wordplay.
'key' becomes 'alt' (I've seen this in other clues).
'by' says to put letters next to each other.
'end of' indicates one should take the final letters.
The last letter of 'solo' is 'o'.
'alt'+'o'='ALTO'
'is' is the link.
Can you help me to learn more?
(Other definitions for alto that I've seen before include "Woman's singing voice" , "someone to sing" , "Key old > male who scores high" , "One who sings" , "The highest adult male singing voice" .)