Kid’s caught with booze in part of music practice (5,5)

'part of music practice' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps you can see a link between them that I don't see?

'kid's caught with booze' is the wordplay.
'kid's' becomes 'minor's' ('minor' can be a synonym of 'kid').
'caught with' becomes 'c' (cricket abbreviation. I am not sure about the 'with' bit.).
'booze' becomes 'ale' (type of alcohol).
'minors'+'c'+'ale'='MINOR SCALE'

'in' acts as a link.

Can you help me to learn more?