It is hard to put a % on this but I prefer Music over Songs. I rarely listen to the words when there are vocals and zero in on specific instruments most of the time. I wish one could purchase the Karaoke versions of everything to suppress the vocals. Of course, much of what I listen to does have vocals and there are exceptions to my rule when it comes to certain vocalists.
As far as Vocals being an Instrument, for me that would be Phil Collins on Trick, And Then There Were Three, Wind & Wuthering. Greg Lake on many of his Solo works like It Hurts. I have always been an Annie Haslam fan along with Mary Fahl and several others. I also dig some of the vocals from Transatlantic - The Whirlwind.
But, if given the choice to listen to Chad Smith and the Bombastic Meatbats or Diana Krall, the latter would lose in a millisecond. I prefer virtuoso instrumentalists and super groups for the most part.
If I had a choice, it would be 80% Instrumental and 20% Vocals.