The bird song that wakes you at dawn? (7,6)

'the bird song that wakes' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'you at dawn?' is the wordplay.
I cannot quite see how this works, but
'you' could be 'u' (homophones) and 'u' is located in the answer.
'at' could be 'in' (synonymous in some cases - eg at school, in school) and 'in' is present in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?