Playing guitar with Thom Yorke initially giving tip (8)
I believe the answer is:
gratuity
'tip' is the definition.
(I know that tip can be written as gratuity)
'playing guitar with thom yorke initially' is the wordplay.
'playing' indicates anagramming the letters.
'with' is a charade indicator (letters next to each other).
'initially' suggests taking the first letters.
The initial letters of 'thom yorke' is 'ty'.
'guitar' anagrammed gives 'gratui'.
'gratui'+'ty'='GRATUITY'
'giving' acts as a link.
(Other definitions for gratuity that I've seen before include "present" , "Tip (to waiter)" .)