Jeeves, for example, introduces Glen to tango (5)
I believe the answer is:
valet
'jeeves for example' is the definition.
(valet in PG Wodehouse's Jeeves and Wooster books)
'glen to tango' is the wordplay.
'glen' becomes 'vale' (I've seen this in other clues).
'to tango' becomes 'T' (phonetic alphabet: alpha, bravo, charlie etc.).
'vale'+'t'='VALET'
'introduces' acts as a link.
I am not very happy about this link. It may be part of another bit of the clue.
(Other definitions for valet that I've seen before include "Gentleman%u2019s gentleman" , "Personal manservant" , "Man's servant" , "Male servant" , "Personal male assistant" .)