Stress fella, openly accommodating singer under proposal (9,4)

'stress fella openly accommodating' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'singer under proposal' is the wordplay.
I cannot really see how this works, but
'singer' could be 'alto' (alto is a kind of singer) and 'alto' is located in the answer.
'proposal' could be 'motion' (motion is a kind of proposal) and 'motion' is found in the answer.
The remaining letters 'ell' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

Can you help me to learn more?