"I'll always do the guitar parts since it's my main instrument"

Trevor Rabin's quote suggests that he has a strong affinity for the guitar and that it is his primary instrument. He is expressing his commitment to playing the guitar parts in whatever project he is dealing with. This could be translated as a sign of commitment and enthusiasm for his craft. He is also implying that he is confident in his capability to play the guitar which he wants to handle the responsibility of playing the guitar parts. This could be viewed as an indication of humbleness and regard for the other artists he is dealing with. It might also be viewed as an indication of regard for the music itself, as he is willing to put in the effort to make certain the guitar parts are played correctly. Overall, this quote is a testament to Trevor Rabin's commitment to his craft and his regard for the music he is creating.