The ups and downs of many a London commuter? (10)

'the ups and downs of many a london commuter?' is the definition.
I can't judge whether this defines the answer.

'the ups and downs of many a' is the wordplay.
I cannot really see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
'of' could be 'o' and 'o' is located in the answer.
'many' could be 'l' and 'l' is located in the answer.
'a' is within the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?