Multi-part dramas on the radio? They can be corny! (7)
I believe the answer is:
cereals
'multi-part dramas' is the definition.
I can't tell whether this defines the answer.
'on the radio? they can be corny' is the wordplay.
I cannot quite see how this works, but
'on' could be 're' ('on' can be mean 'with reference to') and 're' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for cereals that I've seen before include "Starchy grains used as food" , "Grain foods" , "Eg, wheat, rye, oats" , "Foods such as rye, wheat, etc" , "Breakfast foods" .)