Former model in group to begin similar sets (7)
I believe the answer is:
sextets
'sets' is the definition.
(sextet is a kind of set)
'former model in group to begin similar' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'model' becomes 'T' (Ford Model T car).
'in group' becomes 'ets' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'to' means one lot of letters go next to another (I've seen this in other clues).
'begin' suggests taking the first letters.
The first letter of 'similar' is 's'.
'ex'+'t'+'ets'='extets'
'extets' put after 's' is 'SEXTETS'.
Can you help me to learn more?
(Another definition for sextets that I've seen is " Groups of six".)