Pub's line-up includes Alabama and fellow singers (10)

'singers' is the definition.
(balladeer is a kind of singer)

'pub's line-up includes alabama and fellow' is the wordplay.
'pub's line-up' becomes 'beers' (I can't explain this - if you can you should give a lot more credence to this answer).
'includes' means one lot of letters goes inside another.
'alabama' becomes 'al' (abbreviation).
'and' is a charade indicator (letters next to each other).
'fellow' becomes 'lad' (synonyms).
'al'+'lad'='allad'
'beers' enclosing 'allad' is 'BALLADEERS'.

Can you help me to learn more?