Bold daughter joins a band (6)
I believe the answer is:
daring
'bold' is the definition.
(I've seen this in another clue)
'daughter joins a band' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'joins' says to put letters next to each other.
'band' becomes 'ring' (a ring is a band of metal).
'd'+'a'+'ring'='DARING'
(Other definitions for daring that I've seen before include "Bold, willing to take chance" , "'Adventurous, bold (6)'" , "Intrepid" , "Audacity" , "Bold and reckless" .)