I went with them because of their rumble basically, not their 'pitch'. I like to use a bunch of random 808s in my tracks sometimes but then I get a little hesitant to keep them in there because I know that I picked them all at random because of their sonics, none of them are tuned (melodic). Sometimes if you go to tune this 808 after you initially picked it for the thump it had, it loses its original sonics because you have to tune it. Is this a plausible approach? I know there are no rules, but I am really asking for insight. For all you know, that 808 could be a note OUTSIDE of D major, and/or it may not be the root, D, but it sounds good because of the thump it's giving off. Basically, say you picked the key of D major to build your music in. Then you start building your music but with no regard for the 808s note. Say you find an 808 sample you want to work with, so you start your beat with this 808 thump.
I'm really asking this in a sense of NOT tuning your 808s. Of course you can play/tune your 808s to your song so you can pitch them out and play a melodic bass line. A lot of 808 samples can be a random note (G#, F, A, etc.).