Issue a word of thanks for some music (6)
I believe the answer is:
sonata
'music' is the definition.
(sonata is a kind of music)
'issue a word of thanks for some' is the wordplay.
'issue' becomes 'son' (issue can mean someone's offspring).
'a word of thanks' becomes 'ta'.
'for' means one lot of letters go next to another (I've seen this in other clues).
'some' becomes 'a'.
'ta' after 'a' is 'ata'.
'son'+'ata'='SONATA'
(Other definitions for sonata that I've seen before include "A musical form" , "Sat on a kind of composition" , "Musical composition with three or more contrasting movements" , "piece for instrumental soloist" , "Beethoven's 'Moonlight', for example" .)