Long player with the fastest time (6)
I believe the answer is:
record
'time' is the definition.
(thesaurus)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for record that I've seen before include "Note - disc" , "Register - best listed achievement" , "a hole in one?" , "Highest achievement" , "Statement of events - best so far!" .)