Call for attention at the heart of Brahms themes (4)
I believe the answer is:
ahem
'call for attention' is the definition.
(I've seen this in another clue)
'the heart of brahms themes' is the wordplay.
'the heart of' indicates the central letters.
'themes' becomes 'em' (I can't justify this - if you can you should give a lot more credence to this answer).
The centre of 'brahms' is 'ah'.
'ah'+'em'='AHEM'
'at' acts as a link.
Can you help me to learn more?
(Other definitions for ahem that I've seen before include "Excuse me!" , "Polite word to draw attention" , "Half-cough to draw attention" , "Throat clearance to attract attention" , "Cough to draw attention" .)