Bit of song? Song's intro, obviously (6)
I believe the answer is:
snatch
'bit of song?' is the definition.
'snatch' can be an answer for 'bit' (I have seen 'bit of air' mean 'snatch' so perhaps 'bit' could also mean 'snatch'). I'm not certain of the 'of song?' bit.
'song's intro obviously' is the wordplay.
'intro' suggests taking the first letters.
'obviously' becomes 'natch' (I've seen this before).
The first letter of 'songs' is 's'.
's'+'natch'='SNATCH'
Can you help me to learn more?
(Other definitions for snatch that I've seen before include "American kidnapping" , "E. Mediterranean nation" , "Take suddenly" , "heist" , "pluck" .)